Get data from remote REST API (read only)
In case anyone else have the same problem. By replacing the name "Authorization" like this:

  $headers =  array('Notified-Custom-Token'=&gt;'my-unique-token', 'Content-Type'=&gt;'text/json' );


... it worked and I got a success response with code 200. My mistake was to believe that Authorization was a mandatory name in the name/value pair.