As per the description above, you are not able to use the Adobe ExportPDF services through the Adobe Reader, Is that correct?
The record shows that you have an active subscription of Adobe ExportPDF services on your Adobe ID.
If you are using the services through the free desktop version of Adobe Reader, then make sure you are logged in with your Adobe ID and password in Adobe Reader. To download Reader: Adobe - Adobe Acrobat Reader DC Distribution Link: https://get.adobe.com/reader/enterprise/
You can also use the services of Adobe ExportPDF through your online account, Sign in to your account at https://cloud.acrobat.com/exportpdf with your Adobe ID and password to use the services.
Hope this helps, and keep us posted with the results.