It will soon be possible to unlock your iPhone with a mask on your face, via Face ID. This new feature is expected in the next version of iOS (15.4), currently available in beta.
The idea is to be able to reliably use Face ID when wearing a mask, even when wearing glasses. The only condition for this to work properly is to give the device a proper look because analysis will no longer be focused on recognising the whole face but on “the unique features around the eyes to authenticate”. The system works regardless of the type of mask worn.