This is a rear button bracket and cart insert for the PocketPi FE: https://galaxygaming.co.uk/shop/gameboy-zero/gameboy-zero-pocketpi-fe-full-kit/

The bracket allows the buttons to have full travel and the cart insert will never bump into the HDMI socket on the pi.

No need to glue anything down, the parts are held in place by the housing.

Something weird happened to my button cap file so you'll need to scale it down 95%
Rotate the cart insert to sit flat on the print bed.