Enable OAuth2 authorization in your service provider
Enable OAuth2 Authorization in your Google Account
Enable OAuth2 Authorization in your Microsoft o365 Account
Save OAuth2 Client Credentials received from your Service Provider in Email This Issue
Perform authorization to allow Email This Issue access the email service
Authorize Email This Issue to access Gmail accounts
Authorize Email This Issue to access o365 accountsAccess Microsoft 365 Accounts
These are the steps the app cannot perform by itself and needs configuration by an expert with administrative rights at the email service provider.