Not able to get rest_command working

Hi. I am trying to get the following URL to be used as a rest command:

curl --location --request GET 'https://example.tld/webapi/entry.cgi?api=SYNO.SurveillanceStation.ExternalEvent&method=Trigger&version=1&eventId=1&eventName=Door is open&account=username&password=password'

Trying to make this into a rest_command I has written the following snipped:

rest_command:
  door_open:
    url: 'https://domain.tld/webapi/entry.cgi'
    method: get
    headers:
      accept: 'application/json; charset=UTF-8'
      content_type: 'application/json; charset=utf-8'
    content_type: 'application/json; charset=UTF-8'
    payload: '{"api":"SYNO.SurveillanceStation.ExternalEvent", "method":"Trigger", "version":1, "eventId":1, "eventName":"Door is open", "account":"username", "password":"password"}'

But triggering this service yields nothing. Not even an entry in the logs. Not sure if I am using the payload correctly, but from my understanding this should be the same as a parameter right?

Is there a better way to troubleshooting this? For instance to see what home-assistant is trying to send to to server when triggering the service?

Just this would do

rest_command:
  door_open:
    url: 'https://example.tld/webapi/entry.cgi?api=SYNO.SurveillanceStation.ExternalEvent&method=Trigger&version=1&eventId=1&eventName=Door is open&account=username&password=password'

Indeed, that did work. But if i want to use any kind of templating in accordance to:

Wouldn’t I need to use the payloads?

Apparently not. Got it working by using your example and adding the “templating” directly in the URL. Thank you!

rest_command:
  door_open:
    url: 'https://example.tld/webapi/entry.cgi?api=SYNO.SurveillanceStation.ExternalEvent&method=Trigger&version=1&eventId={{ eventid }}&eventName={{ message }}&account=username&password=password'

Also, the following should work:

rest_command:
  door_open:
    url: 'https://domain.tld/webapi/entry.cgi'
    method: get
    headers:
      accept: 'application/json; charset=UTF-8'
      content_type: 'application/json; charset=utf-8'
    content_type: 'application/x-www-form-urlencoded'
    payload: 'api=SYNO.SurveillanceStation.ExternalEvent&method=Trigger&version=1&eventId=1&eventName=Door+is+open&account=username&password=password'