Uploading a user manual to complete GPSR compliance

To complete the GPSR requirement, I need to upload the user manual for each ASIN. there was an upload window for the user manual under the Catalogue--Manage product documents, but now it is turned off. after consulting Amazon seller support, they recommended I convert the PDF document to a URL link and fill it in the "Safety & Compliance" of the product editing page.

my question is how to convert the PDF document to a URL? Thank you