iPhone 11 Face ID

Your front camera and earpiece speaker/proximity sensor assembly cable is paired to the motherboard you can't change the parts because you will lose face Id because the parts will not be paired. The only way to keep face Id is take it to a Apple store or A certified Apple repair store and let them fix it. It doesn't matter where you get the parts it will not work because Apple controls that.

For Face ID issues, I would either get apple to fix it, or see if you can salvage the camera by your self. Like @barriphone stated "Your front camera and earpiece speaker/proximity sensor assembly cable is paired to the motherboard you can't change the parts because you will lose face Id." If you break the camera while trying to replace the screen, you will lose Face ID. Could you upload a picture of the top of the screen by where the camera assembly is located?