Azcopy error "This request is not authorized to perform this operation."
If you are using AAD Token, this error is telling you that you need to add a role assignment to the user. Please go to Storage account -> Access Control -> Add -> Add role assignment, then add Storage Blob Data Owner to your login account.
If this problem persists, please provide more details.
When I had this, I discovered it was because I'd used Azure Storage Explorer to generate a SAS that didn't have read permission, and I think it was trying to read the size/existence of a blob before writing it.
I got a clue from https://github.com/Azure/azure-storage-azcopy/issues/790 but ultimately I just regenerated a new SAS with read permission and it worked out..
I probably could ahve looked to modify the C# code using Azure Data Movement lib, to not perform a length check, but the spec was later changed to "don't overwrite" so the read permissions are probably needed anyway