Foot position should be in line with your legs. In a narrow stance squat, I can’t picture anything other than your knees pointing straight ahead. That means your feet should point straight ahead.
If you want your feet to point out then you’ll need a stance that allows your knees to go that direction.
I’m having a hard time describing this so here are some pictures.
Narrow Stance (toes out)
I didn’t even know that last one was a thing but notice how the knees always stay in line with the feet during the movement.
I’ve never done that last version but it looks like it would load the outer hip (glute medius) more than anything else. I’ve always felt more inner thigh (adductors) activation with a wider stance. I’ve noticed it on deadlifts, Romanian deadlifts, and squats.
I hope this helps. The simplest answer is to try different things and see how it feels. If it doesn’t do what you want then try a different movement and continue until you find your favorite.