No Authentication Method for Refreshing Data Source from Exchange Outlook

Hi Everyone, good afternoon.

I have already linked the Attachment from Exchange Outlook Mailbox onto PowerBi Desktop and uploaded it to PowerBi Service.

However, the refresh function cannot be scheduled, it shows 'Your data source can't be refreshed because the credentials are invalid. Please update your credentials and try again.' & there is no Authentication Method under Edit Credential Tab for Exchange but other data sources (Python).

Thx v-xicai PBICommunity 

Best regards,

Echo