Message on webhook notificaion

I am sending an API put method over webhook. The main parameters that forms part of the URL is being received by the external party. However, the embedded message section on Grafana is not received at the moment. Here is the message section under Alerts – Notifications:

That message section is not available as part of the payload received from the third party.

What feature must be enabled in order for this message to be received and this section to be functional?

Please let me know or relay this request to the appropriate support team.

Thank you,