Asking fo best-practice for effective backup of the CAS server db

we are migrating our installation from the obsolete Streamserve to ExStream 16 with CAS and versioning management on SQL EXpress server.
Before the migration, the project files were on the file system so, once versioning had been set up on the files with any versioning program and a backup of the "projects" folder, everything was fine.
Now on CAS however, fortunately during the internal testing phase, we had a problem on the server machine on which SQL EXpress is installed with the CAS server (and the otds). And we were trying to understand (and here I ask you) what is the best practice for the backup and eventual restore of the CAS SERVER DB.
We have already explored the idea of taking a daily snapshot of the virtualized server machine but the doubt that arose was: even if I keep 15-20 days of snapshots saved, if in that period of time I have not noticed an error on the VM , even the oldest snapshot will still contain the error and I will have no way to restore it.
So our idea was to focus on effectively backing up the DB directly. And for this I ask for your support.
Thank you