Re: Connect Sharepoint Calendar in Powerapps Canvas App
Is your Calendar a view from a SharePoint List? Or is a Classic SharePoint Calendar? In the first case, it should appear, in the second I dont know. But one important thing about this is the data from de calendar is a list, if you want a calendar in Power Apps you must create it by yourself.
Anyway, try to paste the link directly here and click Connect:

Let me know if my answer helped solving your issue.
If it did please accept as solution and give it a thumbs up so we can help others in the community.