I'm trying to find out how to get my ipad to have files available locally (if/when I'm not connected to the internet) but that are also synced with my desktop. IPad OS Version is: 15.4.1
I'm sure the standard answer is to use Apple iCloud, but if possible because I'm running windows I'd prefer Google Drive, O365 OneDrive or Dropbox.
Dropbox: First tried dropbox (see https://help.dropbox.com/installs-integrations/mobile/access-files-offline). It required an upgrade. I no longer have premium paid for version of Dropbox, but do have Google Drive, and O365 OneDrive for Business.
Tried OneDrive for Business. Opened the app and was able get files to appear on iPad but can't get them to be available offline and wasn't able to get Apple's File App to see OneDrive.