reddit api 403 forbidden - php

Question

I have the following code;
It all works and I am able to obtain an access token but I get a 403 Forbidden Error when trying to use the submit endpoint. I saw a previous post that uses identical code pretty much, that mentioned that the endpoint is incorrect, Original Post.
I can't seem to find the updated endpoint; Is anyone familiar with the reddit api and would be able to help find the problem here. Thanks :-)
<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
$clientID = '****'; // app client id
$clientSecret = '****'; // app secret
$redditUsername = '****'; // reddit username
$redditPassword = '****'; // reddit password
// Post to subreddit info
$title = '****';
$r = '****';
$kind = '****';
$url = 'http://example.com';
$ch = curl_init('https://www.reddit.com/api/v1/access_token?grant_type=client_credentials&username=' . $redditUsername . '&password=' . $redditPassword . '');
curl_setopt($ch, CURLOPT_USERPWD, '' . $clientID . ':' . $clientSecret . '');
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$return = curl_exec($ch);
curl_close($ch);
$token = json_decode($return, true);
print_r($token);
$ch = curl_init('https://www.reddit.com/api/v1/submit?kind=link&sr=' . $r . '&title=' . $title . '&r=' . $r . '&url='.urlencode($url));
curl_setopt($ch, CURLOPT_USERPWD, '' . $clientID . ':' . $clientSecret . '');
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Authorization: bearer " . $token['access_token'] . ""));
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$return = curl_exec($ch);
curl_close($ch);
$response = json_decode($return, true);
echo '<br><br>';
print_r($response);
?>