How to lock doors when setting armed status to SHM "Armed"?

I am kinda new to smarthings so please help me out.

How can i lock doors when I set my smart home monitor mode to Armed?

Most of the other topics are how to set Armed when a lock is turned. So this is different.

Thanks

Use a Routine to set SHM to armed and lock the door. You can enable/disable SHM in Good Morning!, Good Night, Goodbye! and I’m Back!