ID or Username in SUB

SO, great tutorial, but I believe there is a mistake in the JWT part in
https://christophergs.com/tutorials/ultimate-fastapi-tutorial-pt-10-auth-jwt/

When you create an JWT you put in the user id underneath SUB
And when I go to the endpoint /me
you use the same sub (with user id) to put it in username and try to search for a username that is actually a user id.

Or is there something I do not see?