What is the Microsoft Graph API endpoint to restrict guest user access to Microsoft Teams? I want to prevent guests from being added to teams when the team is being created via https://docs.microsoft.com/en-us/graph/api/team-put-teams?view=graph-rest-1.0 call.
You control this on the underlying Group object, not the team itself. Here's the Graph call to use: https://docs.microsoft.com/en-us/graph/api/directorysetting-update?view=graph-rest-beta&tabs=http
According to this https://docs.microsoft.com/en-us/graph/api/resources/group?view=graph-rest-beta this have "allowExternalSenders" - is this what you are saying?
No, I'm talking about the actual directory settings which control group behavior. If you are not familiar with them, read here: https://docs.microsoft.com/en-us/azure/active-directory/users-groups-roles/groups-settings-cmdlets