I’d soak it in some penetrating oil first (Plus gas or similar).
You can strip the splines off the cassette if you go all-out gorilla on it. Make sure the cassette tool is very well engaged. Make sure the splines on the tool are long enough – I bought a second tool with longer splines for my XD cassette. Sometimes you can use a QR to hold the tool in place (depends on the tool), which helps. Use a cheater bar as above. Go carefully.
I am apprehensive about the next time I have to change my cassette. I haven’t had it off for a long while and it may well be seized like yours.
EDIT: if your bike is a 2020 model it can’t be that old. It’d be unfortunate if it had seized.