"code" index not defined in callback.php?

[amanuelanteneh]

I'm trying to follow the authorization code flow example from here

My auth.php is basically the same as the docs:

require 'vendor/autoload.php';

$session = new SpotifyWebAPI\Session(
    'clientid',
    'secret',
    'http://localhost/callback.php/'
);

$state = $session->generateState();
$options = [
    'scope' => [
        'playlist-read-private',
        'user-read-private',
    ],
    'state' => $state,
];

header('Location: ' . $session->getAuthorizeUrl($options));
die();

And my callback.php is:

require 'vendor/autoload.php';

$session = new SpotifyWebAPI\Session(
    'clientid',
    'secret',
    'http://localhost/callback.php/'
);

// Request a access token using the code from Spotify
$session->requestAccessToken($_GET['code']);

$accessToken = $session->getAccessToken();
$refreshToken = $session->getRefreshToken();

// Send the user along and fetch some data!
header('Location: index.php');
die();

But I keep getting this error: Undefined index: code in {projectPath}\callback.php on line 12. I'm not sure why the code index seems to be null. I tried changing $_GET to $_REQUEST like another issue suggested but that yielded the same error.

[amanuelanteneh]

If anyone else is having this issue, for some reason when I include the extra "/" at the end of my redirect URI this error occurs. However when I omit the "/" and instead use: http://localhost/callback.php as the redirect URI the issue resolves itself. Also make sure to omit the "/" when you whitelist the URI on your apps dashboard as well!