Any "fix" is going to entail polishing. Lots of polishing for a scratch that deep. Which will also look obvious. Since most screens nowadays have an anti-glare coating. Which will be rubbed off. Necessitating doing the entire screen to remove all the coating.
I'd say just live with it.
If you want to do something. Try a matte screen protector. That is the right size for your screen. Be sure to clean the screen extremely well. Maybe take a pencil eraser to the scratch and rub down the burrs along the scratch edge. Then clean and apply the protector.
The reason I say to try a screen protector. Is they can hide scratches. I don't know what limit they have in hiding scratches. They made the ones on my phone disappear.