Sure you can! As long as you present as your preferred gender FT then you are FT! For most guys it can be a problem hiding the chest but that doesn't say you are not living your preferred gender, most girls have problems tucking, same issue different body parts!
If you need it to be recorded by your medical people just tell them. To be honest going FT for guys can be pretty easy as 'society' will not label you as readily as they can a new girls going FT. Once on T guys can have dramatic facial and body changes.
