Yeah it works the same as iPhone X, Xs, X Max, and XR. The FaceID camera uses infrared to map your face, not surrounding light. So darkness doesn’t matter. I haven’t even been effected by direct sunlight with it either.
Just make sure your face isn't too close. This often happens with me and my iPhone X/XS.. Face ID often fails in the middle of the night until I realize I'm holding the phone too close to my face. has to be about half arm's length or so.