Please go to Microsoft App Registration Portal https://apps.dev.microsoft.com/ and create a newapplication, and in the line 22 set the client_id to Client ID and client_secret with Client secret. The callback URL must be https://18.142.0.193/webmail/modules/OAuthIntegratorWebclient/Classes/OAuthClient/login_with_microsoft_openid_connect.php but make sure the domain is valid and can be resolved by a public DNS.