@LauraneSchaerer - if you are referencing the email delivery of notifications/alerts from a Qlik Cloud tenant, it is only possible to utilize a SMTP connection using Basic Authentication (though, I personally prefer the delivery via native notifications through the mobile app on iOS or Android to email).
It is possible to use the OAuth2 REST API connector in Qlik App Automation (QAA) to communicate with Microsoft's Graph API, however it would be easier to utilize the Outlook 365 connector if using QAA.
