KBackup is a helpful KDE backup tool. I use it to backup my Obsidian vaults.
Install using
sudo apt install kbackup
Open the GUI and configure the profile. Set the backup properties and store the profile.
Add this to the crontab
0 2 * * * /usr/bin/kbackup --verbose --autobg /home/avneesh/KBackup/obsidian_vault.kbp