The Application Name will be displayed to users when they attempt to register via Microsoft.
The Supported Account Type is Personal
The Redirect URI type is Web and should be set to <XF board URL>/connected_account.php. For example, https://xenforo.com/community/connected_account.php. The beginning of this URL must match your Board URL setting in XenForo exactly. If you are able to access your site from both www. or a non-www. domain name, you will need to both these as possible Redirect URLs. HTTPS is required.
Click Register
Note down the Application (client) ID
Click Certificates and Secrets in the left hand menu.
Click New Client Secret
Give the Secret a Name and set the expiry date to Never