Proper Shutdown For RPi Makecode Arcade Console

I’m making game consoles in cigar boxes using the rPi B+ since the Zeros are very scarce. I held on to them for years thinking some day there will be a use for them.

What I don’t see in the MakeCode Arcade OS ( arcade-cardboard) is a way to properly shut down the pi. Can someone please help me with that?

Thanks!
Karen G