How do I get to any menu while emulating

I’m emulating games on emu deck and yuzu but the steam button and the button with three dots won’t work. I can’t close the games without powering down the system. I’ve searched for easy to fix this but nothing is what I’m looking for. I want to tweak performance and minimize games, is there anyway to do this without mapping buttons for every single game. If so, which buttons do I map.