Discord Notifications - adjust message body

Is it possible to adjust the message Body of Discord-Notifications in any way?

I try to enhance the Discord-Notification to contain the User-Name.

If a MR-Request is assigned to user “fritz”, I want to be able to talk straight to the discord-user “fritz9909” in the discord-channel.

To archive this I would need following:

  1. a case-based mapping (git-user > discordUser)
  2. possibility to adjust the Discord-Message that will be send