I did some experiments in the past. The nicer option I could find was enabling webdav API on the hosting side (it was an option on cPanel if I recall correctly, but there are likely other ways to do it). These allow using the webserver as a remote read/write filesystem. After you can use rclone to transfer files, the nice part is that rclone supports client side encryption so you don’t have to worry too much about other people accessing files.
I did some experiments in the past. The nicer option I could find was enabling webdav API on the hosting side (it was an option on cPanel if I recall correctly, but there are likely other ways to do it). These allow using the webserver as a remote read/write filesystem. After you can use rclone to transfer files, the nice part is that rclone supports client side encryption so you don’t have to worry too much about other people accessing files.