This exercise is quite tricky and most people that have a bunion or their first toe is drifting to the outside, have trouble at first because this muscle is quite weak.
First, try splaying your toes. See if you can move your toe to the outside. Not up into the air (which is what most people can do) but out towards your other foot. <insert picture>. Place your fingers on the inside aspect of your foot. You should feel the muscle contracting as you splay your toes. If you are having trouble with this, don’t worry. It will take a lot of practice. If you feel tired or crampy, this is normal.
Take a break and practice again later. Doing this exercise will really make a difference for you in the future in terms of your toe drifting to the side and potentially causing your second toe to cross over your first toe. The stronger you can make this muscle (even moving it a few millimetres) may make a big difference to you buying shoes that are deep enough and in terms of comfort in the long run. Make sure you diligently do this exercise to keep you abductor hallucis longus strong.