Like this one?
Assuming it's truly dead, pull the old one, get dimensions and buy something matching. I've seen anecdotal evidence that greystone makes identical sizes (down to the mounting screw holes) to the Magic Chef branded ones, not sure about 2014, tho.
Are you sure it's dead? Internal fuse is a common problem with microwaves. Could be as simple as a $5 fix.
2022 Rockwood Roo 235S
2017 Audi Q7 3.0