Can i send different Logs to different Indicies?

[Moritz_Kiesewetter]

Hello Community,
by now, my config file for incoming Logs looks like this:

input {
  udp {
    port => 5140
    type => syslog
  }
}

filter {
  syslog_pri { }
  date {
      match => [ "syslog_timestamp", "MMM  d HH:mm:ss", "MMM dd HH:mm:ss" ]
    }
  if [message] =~ /devname=/ {
    kv {
      source => "message"
    }
    mutate {
        convert => { "cpu" => "integer" }
        convert => { "mem" => "integer" }
        convert => { "disk" => "integer" }
        convert => { "totalsession" => "integer" }
        rename => { "type" => "fgt_type" }
        rename => { "subtype" => "fgt_subtype" }
        add_field => [ "type", "syslog" ]
        add_field => [ "fortilog", 1]
        lowercase => [ "vd" ]
   }
  }
  if [message] =~ /-esx-/ {
    if [message] =~ /^\S+ \S+ \S+ \S+: \S+ \S+ \[Originator@\d+ [^]]+\] .*$/
    {
      grok {
        match => [ "message", "\S+ \S+ (?<syslog_hostname>\S+) (?<esxservice>\S+): (?<level>\S+) (?<esxprocess>\S+) \[Originator@\d+ (?<esxsubinfo>[^]]+)\] (?<esxmessage>.*)" ]
      }
      kv {
        source=>"esxsubinfo"
      }
    }
    else {
      grok {
        match => [ "message", "^\S+ \S+ (?<syslog_hostname>\S+) (?<esxservice>\S+): (?<esxservicemessage>.*)$" ]
      }
    }
  }


}

output {
    if [type] == "syslog" {
      elasticsearch {
        hosts => ["X.X.X.X:XXXX"]
        index => "logstash"
  }
  }
}

If i now want to send the logs, which recieve the file "fortilog : 1", to a different indicie how can i manage that?
I've tried to to something like this ;

if [fortilog] == "1" {
  elasticsearch {
    hosts => ["X.X.X.X:XXXX"]
    index => "SampleIndex1"
}
}
   else 
   elasticsearch {
        hosts => ["X.X.X.X:XXXX"]
        index => "SampleIndex2"
}
}
}

But this does not seem to work, as i'm not able to create index pattern even if i create the index manually.

Any ideas?

Thanks in advance.