How are actionable notifications processed coming from MS Teams?

[Lilla Murger]

Our instance has an integration with MS Teams, our users can take action for notifications they received by clicking on a button. The function behind the button deletes a subscription record. This seems to be only working for users with itil role. 

During investigation I observed that the Outbound HTTP request for the failing execution are created by Guest user and the source is empty. When the logic executes successfully, the created by field is populated with the user's ID and the source record is Business Rule: Process inbound message.

When I go to the Inbound message table, I see that the there are message records in Error state, these are in line with the failed testing time stamps. 

The business rule only has the condition for the state, which should be Pending. I played around with this, removing the condition does not make a difference. The executed function looks to be hidden: sn_notification.Messaging.processInbound(current.getUniqueValue());

I would like to understand the whole flow so that we can enable end users interacting with ServiceNow through MS Teams Messaging buttons regardless the role of the user. My main questions are:

- What creates the messaging inbound record? 

- Do we have information of sn_notification.Messaging.processInbound?

- What logic should recognize based on the payload the ServiceNow user record?

Any help is appreciated, thank you in advance! 

(Also, Happy New Year! :))