MS Teams recieving no GE Notifications

[Yamden]

Hello,
I've been trying to trigger GE notifications by a MS Teams webhook rather than Slack. I have set up the checkpoint config as follows (using a SimpleCheckpoint):

 {
   "name": "send_teams_notification_on_validation_result",
   "action": {
     "class_name": "MicrosoftTeamsNotificationAction",
     "microsoft_teams_webhook": "${teams_webhook}",
     "notify_on": "all",
     "renderer": {
       "module_name": "great_expectations.render.renderer.microsoft_teams_renderer",
       "class_name": "MicrosoftTeamsRenderer"
   }
 }
 }

And I have set the MS teams url in config_variables.yml as teams_webhook . Yet when running an expectation I receive no notifications, am I missing a step somewhere?