TouchID as well as FaceID is tricky things because of a number of security features embedded within them. Also FaceID does not really only work through the front facing camera but through sensors within the notch that are, I think, sort of Infrared sensors reading ones face. Also, both identification methods are linked to the iPhones Logic Board by a unique ID which means that replacing the screen and not using the old home button will not have a working fingerprint sensors, and also there are no aftermarket displays that have a working FaceID scanner built in, and even if they had, it wouldn't work because it is not linked to the iPhones internals. The front facing camera may work though, but FaceID will not. Taking it to Apple is the only way to get all the features into working other again, and according to Apples support website, a screen replacement for an out-of-warranty iPhone XS Max is 329$. Depending on how much you spent for the phone in the first place, and what condition it is generally and how good the battery is still, I may not be worth doing that! And also what QuickTimeKirk said, they may not even attempt to do anything about it.