 <ol> <li><p>You're using the GET method, which gets an app link url that was already created using the API, but will not create new ones.</p></li> <li><p>You can't create them from mobile devices since they require an app access token (not a user access token). If you look at the "Publishing" section of the documentation, you'll see that there's no Android or iOS code snippets.</p></li> <li><p>For detailed instructions on how to create an app link hosting url (from the command line, or server side), follow the steps here: <a href="https://developers.facebook.com/docs/applinks/hosting-api" rel="nofollow">https://developers.facebook.com/docs/applinks/hosting-api</a></p></li> </ol>