I tried the "Mobile and desktop" type setting and received a 'Application successfully authorized' message in Edge. But later I received the following response (using Fiddler):
"error": "invalid_client",
"error_description": "AADSTS7000215: Invalid client secret is provided.\r\nTrace ID: 9835b016-20a9-4ff6-b3e0-44910725dd00\r\nCorrelation ID: 43f4b25d-6762-45f8-a9ed-3db53ee72f50\r\nTimestamp: 2021-08-18 16:01:28Z",
I had received this same error previously and changed the Secret key to a new one (expiring 19/08/2023) in Azure 'Certificates & secrets' . That makes no difference. I have got Dropbox and Google Drive working (albeit with the bug reported earlier in Google). Does your TMSFNCCloudStorageServices VCL demo still work for you with OneDrive?