if it has water in it the door won't open,you can try unplugging it or flip the breaker,wait a few minutes and then put power to it and see if the door will open,if not pull the drain hose out of the stand pipe or sink,get it as close to the ground as you can and with a shop vac suck the water out through the drain hose,or you can unplug the machine remove the top panel and on the bottom of the door switch there's a round ring,you pull it down to manually open the door.go here to see.
https://www.repairclinic.com/PartDetail/Door-Lock/WP8182634/1094190
you see the round ring on the bottom grab it and pull it down and that will release the door,if it's not drainiing you'll have to take it apart and get to the pump,remove the hoses and see if anything is stuck in the pump or hoses,also you can remove the plastic hose that goes to the pressure switch and blow through it to see if soap is blocking the opening where it connects to the tub.blowing down into it will hopefully open it up if it's blocked if not remove it and clean out where it connects to tub or stuff in hose with a paper clip.but puling down on door switch will manually open the door.