No you should not cook a beyond burger in the microwave because it does contain fat which doesn't cook well in the microwave.
If you want to cook a beyond burger properly you should either grill the beyond burger or cook the beyond burger on the stove in a skillet.
I once tried microwaving a beyond burger and fat and grease got into the microwave and the beyond burger did not turn out properly.
It did cook but it was not very appetizing and will no longer use the microwave to cook a beyond burger but the beyond burgers are delicious when cooked on the grill or on the stove in a skillet.
If you do microwave the beyond burger it won't be as good tasting and you'll have a mess to clean up in your microwave.