Washing machine won't drian water

Take the hose off the back and place it in a bucket

If the water gushes out you either have a coin or a grip stuck in the pump , take out the lint trap and try to dislodge it

If the water trickles you have a small item of clothing in the hose leading to the pump, that means letting the water out using the bucket method then removing the hose from the outer tub to the pump