External users scanning to our Sharepoint

Hi All, we are moving away from FTP in our environment and in that process I am trying to figure out a way our external users can scan their documents into our SharePoint. We are providing them with the scanner. Is there a way we can allow guest accounts in Azure to access One Drive so they can sync the SharePoint folder to their PC?

Some more information. We are a vendor and our customers each have their own environment.

Thank you,