However, here's what we can consider:
* He's an actor: Tyler James Williams is primarily known for his acting abilities. While he might be able to sing, it's not his primary profession.
* Musical movies often use voice doubles: In movies with strong musical components, it's common for actors to be dubbed by professional singers.
* There's no official confirmation: There haven't been any public statements or interviews where Tyler James Williams has explicitly stated that he's singing the songs himself.
Therefore, it's likely that Tyler James Williams is singing some of the songs in the film, but not all of them. It's also possible that he's singing some parts, and a professional singer is filling in the rest.
It's best to enjoy the film and appreciate the musical talents of the performers, regardless of who is actually singing.