Place brisket fat-side up on a rack inside an electric pressure cooker. Sprinkle garlic powder and onion powder over brisket; pour beer into the pot.
Seal pressure cooker and cook beef on the "meat" setting according to manufacturer's instructions, about 1 hour 30 minutes. Allow pressure to release naturally according to manufacturer's instructions.
Transfer brisket to a cutting board. Remove top layer of fat from the brisket. Slice across the grain using an electric knife.