How is this singer doing this?

Hello all,
I am curious on how this singer is singing this song (your love-outfield). Is he constantly singing in mix voice? is this chest voice? or head voice? The voice sounds very stable, how is he doing this!?
https://www.youtube.com/watch?v=EnQicyW_6-Y
I am curious on how this singer is singing this song (your love-outfield). Is he constantly singing in mix voice? is this chest voice? or head voice? The voice sounds very stable, how is he doing this!?

Comments
He is also singing into the mask, to give it a little extra ring.
When he goes down to his lower notes, he lets a little more girth into the sound. When he goes up to the higher "I don't wanna! I don't wanna!" those have almost zero girth and just a thread of chest for timbre. You can also hear the mask there.