Nextcloud
A folder shared by link on your own cloud works as well as one in Google Drive.

Not everyone keeps their documents with Google. Nextcloud runs on servers its users choose: at home, at their organization, at a provider they trust. Foldocs reads a Nextcloud folder just as it reads a Drive folder, through nothing but its share link.
Setting it up
- In Nextcloud, share the folder with a share link, read only. A password is fine.
- Give Foldocs the link (and the password) instead of a Drive folder and key. No account or key is needed.
What's different
Nextcloud keeps documents as files, so pages there are Word files (.docx); set your office app to save as Word rather than OpenDocument. A share has no descriptions, so photos get no captions. Everything else works the same: sections, subsections, dates, numbers, photos, themes and the design document.
More in Share a folder.