Azure sql database export to storage blob failed

I had the same problem. I have contacted Azure support and this is their response.

We recently identified a regression in the import/export service that is generating incorrect SAS tokens to the storage accounts.

The engineering team has rolled out the fix, but it might take some time for the fix to get applied worldwide.

Please try the following link to access Azure portal and then perform the export operations:

The portal shows an orange title bar if you open it via the above link, this is expected.

So, it should be already fixed by now.