I use this safe.
Amazon Basics Steel, Security... https://www.amazon.com/dp/B00UG9HB1Q?ref=ppx_pop_mob_ap_share
It fits my Glock 43, Glock 26 and Glock 19 and has a little room left over. These are my carry guns I rotate between and they all are stored loaded in their holsters in the safe. It works well and I’m happy with it for the price.
Something like this would likely be sufficient: https://www.amazon.com/dp/B00UG9HB1Q There are a few different shapes and sizes of this style lockbox.