Hi Paul
You can access to My Downloads menu item
joomdonation.com/my-downloads.html
, download the extension from there and update to your site manually
Or better, access to
joomdonation.com/download-ids.html
, generate Download ID for your account. Get that Download ID, enter it into Download ID config option of Documents Seller and then you can update to latest version of the extension from administrator area of your site
Please do that and let us know if you still have any other questions
Regards,
Tuan