The page states
"Login is handled by Xbox Live, which is out of scope of this page. To authenticate with the endpoints, you need an Authorization header set with an XBL-3.0 Xbox Live service token."
Which I understand, seeing how complex the authentication with OAuth and Azure can be. However, this seems to be so involved, that it does warrant an explanation or at least a referal to such an explanation. I would agree that it's not part of this article, but that it should be included in some form, possibly in its own page.