How can I backup Linux Ubuntu 20.04 VPS to Google Drive or Windows?
Solution 1:
Yes, Timeshift is open source. It's in the Ubuntu repositories.
Yes, Timeshift can be controlled from the shell (CLI).
Google Drive --which requires OAuth-- requires a bit of additional software and an API Key to use as a backup storage device. Those hurdles were put in place by Google, not us.
A Windows system requires an SSH server. If that LAN doesn't have a consistent IP address, then a DDNS client may be useful, too. And, of course, you must port-forward the Router so Timeshift can find the PC.