changing the behavior of the alt key of an existing app

[shmerlard]

hi, im new here so I hope its the right place,
hi, im using Lyx which use Qt6.7.2 on wayland, arch linux with kde6

and for some applications the alt key toggles the menu bar, but for lyx it doesnt, but if i press alt+f for instance the file menu will show, which is a problem since then i wont be able to se shortcuts for alt+f in lyx, a few months ago i remember that all i had to do was to press alt and then the key,

is there an option to add an env' variable to change the behavior?