Step on another switch to activate another moving pathway.

Dodge the boss’s attack and the path will take you to an area with three green switches on the wall and two orange monsters pacing up and down in front of them.  You need to shoot those three switches to unlock the exit.  The orange monsters can’t attack you but they will get in the way of your shots.

If you find shooting the switches difficult then you need to relax, breathe slowly, wipe the sweat off your palms, and practice walking around and around on the moving pathway.  The pathway ends up making loops and you can walk around those loops indefinitely.  There’s no time limit, so just keep following the path and take occasional shots at the switches until the exit unlocks.