<?php 
function shortenVideoUrl($longUrl) {
    $accessToken = 'YOUR_ACCESS_TOKEN'; // replace with your Bitly access token
    $url = 'https://api-ssl.bitly.com/v4/shorten';
    $data = array(
        'long_url' => $longUrl,
    );
    $headers = array(
        'Authorization: Bearer ' . $accessToken,
        'Content-Type: application/json',
    );
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    $result = curl_exec($ch);
    curl_close($ch);
    $response = json_decode($result, true);
    return $response['link'];
}

?>