Most secure way to take daily backups of my PWs on my Linux server

I have a premium BW plan. I have a Linux server at home. I want to take regular backups of my vault on my server in case BW ever goes down or becomes unavailable.

I figured out I need to use the CLI with login, sync, and export. But it says saving the session key is dangerous.

Is there a more secure way to create a cron job to auto backup my vault?