How to print my error stack trace from watchers or/and alerts in an email?

[Rem]

The title said it all.

"actions": {
        "email_action": {
          "throttle_period_in_millis": 900000,
          "email": {
            "profile": "standard",
            "to": [
              "myEmail@SMTP.com"
            ],
            "subject": "{{ctx.payload.hits.total}} Errors have occured in the logs",
            "body": {
              "text": "{{ctx.payload.hits.total}} Errors have occured in the logs in the last X minute. You can check the latest in the below link",
              "html": "Error name or error stack trace: {ctx._source.@timestamp} {{ctx._source.@timestamp}} {{ctx.payload.hits.2._source.@timestamp}} {{ctx.payload.hits.3._source.@timestamp}}"
            }
          }
        }
      },

That does not work. Any cue?

[Marius_Dragomir]

Are you getting any errors when running that or just not displaying any results?

[Rem]

Sorry for my late reply.

I'm not having any errors because I receive the email.
In the email, it is not displaying any results often replacing the variable by blank.

Like that:
HostName

&& && Query Link: https://URL [{ctx._source.@timestamp}]

Between the '&', there are only blanks.