i backup my files, incl keepass to my proton drive using Syncback which i paid for (thanks Warwagon!). they have a free version but i can't remember what it does and doesn't do anymore. anyways, it's really, really simple and easy to use. i also periodically keep backups of my keepass onsite especially when i've changed or added a password that is important to me.
if you don't wanna spend time on the syncthing setup, get syncback. haha i even got my dad to use it for his backups to usb and he doesn't even need my help!!! (thank god!)