If the microwave is brand new, be sure to check with the company that made the microwave, and the store from which you bought it. You may have a warranty, or may have purchased some kind of protection plan when you bought all your appliances.
I was pleased to find out that I had such coverage when a guest broke the top panel of my microwave, where the filter is. A repair person came out and replaced it for no charge.
I also have had dishwasher parts repaired twice when guests have stuffed too many dishes in it and broke the rack’s side slider. Again, no charge.
I normally don’t buy any kind of extra warranty or protection plans for new appliances, since hardly anything ever happens with normal use. However, I have found such plans invaluable when guests are involved. They can be so rough on things.