If above error message are not indexed not sure why but able to see output of below search query by searching with above timestamp in dev-api-000001 index (except for 1635153355844 ).
GET /dev-api-000001/_search
{
  "query": {
    "match": {
      "time": "1635147923598"
    }
  }
}
{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "dev-api-000001",
        "_type" : "_doc",
        "_id" : "Me",
        "_score" : 1.0,
        "_ignored" : [
          "message.keyword",
          "json_message.keyword"
        ],
        "_source" : {
          "type" : "dev-api_app_server2",
          "host" : {
            "os" : {
              "type" : "linux",
              "version" : "7.9 (Maipo)",
              "codename" : "Maipo",
              "name" : "Red Hat Enterprise Linux Server",
              "platform" : "rhel",
              "kernel" : "3.10.0-1160.45.1.el7.x86_64",
              "family" : "redhat"
            },
            "ip" : [
              "<App_server2_IP>",
              "fe80::250:56ff:fbbe:5994"
            ],
            "mac" : [
              "00:50:56:bb:60:94"
            ],
            "containerized" : false,
            "architecture" : "x86_64",
            "name" : "app_server2",
            "id" : "b4a4",
            "hostname" : "<App_Server_2>"
          },
          "program" : "dev-api",
          "message" : """Oct 25 10:45:23 <App_Server_2> dev-api: {"level":"info","time":1635147923598,"pid":105690,"hostname":"<App_Server_2>","response":{"uri":"https://apiman-con-/con-api/me?fields=email","method":"GET","statusCode":200,"statusMessage":"OK","headers":{"date":"Mon, 25 Oct 2021 07:45:23 GMT","content-type":"application/json; charset=utf-8","content-length":"51","connection":"close","strict-transport-security":"max-age=31536000; includeSubDomains","x-request-id":"e5d947a4fe","etag":"W/\"33-hjv8/5ws\"","vary":"Accept-Encoding"},"body":{"email":"<abc@abc.com>"}},"msg":"external response","v":1}""",
          "level" : "info",
          "pid" : 105690,
          "agent" : {
            "type" : "filebeat",
            "version" : "7.14.0",
            "ephemeral_id" : "e8f",
            "name" : "app_server2",
            "id" : "26",
            "hostname" : "<App_Server_2>"
          },
          "msg" : "external response",
          "time" : 1635147923598,
          "logsource" : "<App_Server_2>",
          "hostname" : "<App_Server_2>",
          "log_type" : "dev-api_app_server2",
          "tags" : [
            "beats_input_codec_plain_applied"
          ],
          "ecs" : {
            "version" : "1.10.0"
          },
          "v" : 1,
          "app_id" : "node",
          "input" : {
            "type" : "log"
          },
          "@timestamp" : "2021-10-25T07:45:23.598Z",
          "log" : {
            "offset" : 6307,
            "file" : {
              "path" : "/var/log/dev-api/server.log"
            }
          },
          "timestamp" : "Oct 25 10:45:23",
          "response" : {
            "statusMessage" : "OK",
            "body" : {
              "email" : "<abc@abc.com>"
            },
            "headers" : {
              "connection" : "close",
              "date" : "Mon, 25 Oct 2021 07:45:23 GMT",
              "strict-transport-security" : "max-age=31536000; includeSubDomains",
              "x-request-id" : "e5e",
              "content-type" : "application/json; charset=utf-8",
              "content-length" : "51",
              "etag" : "W/\"33-hjv8/5s\"",
              "vary" : "Accept-Encoding"
            },
            "method" : "GET",
            "statusCode" : 200,
            "uri" : "https://apiman-con-/con-api/me?fields=email"
          },
          "@version" : "1",
          "json_message" : """{"level":"info","time":1635147923598,"pid":105690,"hostname":"<App_Server_2>","response":{"uri":"https://apiman-con-/con-api/me?fields=email","method":"GET","statusCode":200,"statusMessage":"OK","headers":{"date":"Mon, 25 Oct 2021 07:45:23 GMT","content-type":"application/json; charset=utf-8","content-length":"51","connection":"close","strict-transport-security":"max-age=31536000; includeSubDomains","x-request-id":"e8d947a4fe","etag":"W/\"33-hjv8/5ws\"","vary":"Accept-Encoding"},"body":{"email":"<abc@abc.com>"}},"msg":"external response","v":1}"""
        }
      }
    ]
  }
}
Below is the mapping for request , response field.
  "request" : {
          "properties" : {
            "body" : {
              "properties" : {
                "client" : {
                  "properties" : {
                    "bypassApprovalPage" : {
                      "type" : "boolean"
                    },
                    "clientId" : {
                      "type" : "text",
                      "fields" : {
                        "keyword" : {
                          "type" : "keyword",
                          "ignore_above" : 256
                        }
                      }
                    },
                    "enabled" : {
                      "type" : "boolean"
                    },
                    "grantTypes" : {
                      "type" : "text",
                      "fields" : {
                        "keyword" : {
                          "type" : "keyword",
                          "ignore_above" : 256
                        }
                      }
                    },
                    "name" : {
                      "type" : "text",
                      "fields" : {
                        "keyword" : {
                          "type" : "keyword",
                          "ignore_above" : 256
                        }
                      }
                    },
                    "redirectUris" : {
                      "type" : "text",
                      "fields" : {
                        "keyword" : {
                          "type" : "keyword",
                          "ignore_above" : 256
                        }
                      }
                    },
                   .
                   .
                   .
      "response" : {
          "properties" : {
            "body" : {
              "properties" : {
                "access_token" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
                "api_version" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
                "app_credential_urls" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
                "app_url" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
                "client_id" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
                "client_secret" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
                "created_at" : {
                  "type" : "date",
                  "format" : "strict_date_optional_time"
                },
                "email" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
                "expires_in" : {
                  "type" : "long"
                },
                "id" : {
                  "type" : "text",
                  "fields" : {
                    "keyword" : {
                      "type" : "keyword",
                      "ignore_above" : 256
                    }
                  }
                },
This is the pipeline configuration for dev-api application.
input {
  beats {
    port => 5044
  }
}
filter {
if [log_type] == "dev-api_server1" and [app_id] == "node"
  {
    grok { match => { "message" => "%{SYSLOGBASE} %{GREEDYDATA:json_message}"  } } json { source =>  "json_message" }
    date { match => ["time", "UNIX_MS"]
         }
    mutate {
             replace => {
               "[type]" => "dev-api_server1"
             }
           }
  }
if [log_type] == "dev-api_server2" and [app_id] == "node"
  {
    grok { match => { "message" => "%{SYSLOGBASE} %{GREEDYDATA:json_message}"  } } json { source =>  "json_message" }
    date { match => ["time", "UNIX_MS"]
         }
    mutate {
             replace => {
               "[type]" => "dev-api_server2"
             }
           }
  }
output {
  if [log_type] == "dev-api_server1" {
  elasticsearch {
    hosts => ['http://es_1:<es_port>', 'http://es_2:<es_port>', 'http://es_3:<es_port>']
    index => "dev-api"
    template_name => "dev-api"
    template_overwrite => "false"
        user => elastic
    password => "${es_pwd}"
      }
}
  if [log_type] == "dev-api_server2" {
  elasticsearch {
    hosts => ['http://es_1:<es_port>', 'http://es_2:<es_port', 'http://es_3:<es_port>']
    index => "dev-api"
    template_name => "dev-api"
    template_overwrite => "false"
        user => elastic
    password => "${es_pwd}"
      }
}
Thanks,