Hi Manuel,
Thanks a lot for your reply. Just a couple of points:
1. We are not posting this notification to a Teams channel, instead to specific individual users e.g. the user that created the case or the user who's queue the case is in.
2. The URL isn't constant. In other words, it's not a hard coded URL. The URL is to take the user to the specific case in the model-driven app, about which the notification is for.
Apologies for not clearly stating these points earlier.