Stand on a stable raised surface with feet close together (narrow stance). Brace your core and keep your chest up. Bend at the hips and knees to lower into a squat, keeping your knees aligned with your toes and back straight. Go down as far as comfortable, ideally until your thighs are parallel to the floor, then push through your heels to stand back up. Repeat for reps.
Log your narrow squat from deficit sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.