The door latch (AP3776470) probably broke or one of the keepers that hold it in place broke so now the button no longer releases the door. If you remove the upper grill and then the control panel (one screw on top then slide it up) you should be able to see what is happening. Unplug the unit before poking around inside, but you should be able to release the door. But if the latch is broken or out of position, then the interlock switches will not be closing, thus the microwave will not heat.

I just reread my first reply and gave you some information that is incorrect for your model. Need to stop doing two things at once.

Yes you will need to remove the wrapper and to do that, you will need a Torx (that is the star with the center post) which is available at most hardware stores. They are used as a deterrent to people getting in and doing repairs without first asking questions. Once the wrapper is removed, you will be able to see the push button and door release lever, along with the interlock switch mount. If the door isn't opening, something in that setup is loose or fell off. Take a look and see if anything is loose and get a feel for how the door releases when the button is pressed. A common failure on these is the button not being able to fully depress the release lever due to a broken tab that falls between the button and the lever. Under the over, there should also be a tech sheet describing how the components work and testing procedures if we are looking at two separate problems.

What is a wrapper and how do you remove it? It seems i am having the same problem where the one touch open button is not working to open the microwave door.