Post a picture of it, the basket and the mesh.
If it’s really bad then like someone else suggested: get some oven degreaser from the store, spray it down, let it sit for 10 minutes and wash off with hot water. Try not to breath the stuff, it’s nasty.
But you should be cleaning it weekly. Warm it up for a minute or two, then with folded paper towels wipe it out over a trash can. Leaving a light coating is actually to your advantage, it will keep the new stuff from sticking.
Yeah it’s pretty caked on. At this point if you want to clean it, let it dry out and then use some oven cleaner, it comes in a can sort of like spray paint.
Read the directions and follow them just like an oven. Except that you can use plastic bristled brush to agitate and running hot water to wash it off.
https://a.co/d/gF7wTx0