CloadFlare Direct creator uploads

Cloudflare supports the direct creator uploads with the tus client as mentioned here https://developers.cloudflare.com/stream/uploading-videos/direct-creator-uploads/#step-2-use-this-api-endpoint-with-your-tus-client

`
$client = new \TusPhp\Tus\Client( 'https://upload.cloudflarestream.com/XXXX');
$client->setApiPath('/api');
$upload_key = uniqid(); // Unique upload key.
$client->setKey( $upload_key );
$response = $client->file( , )->upload( 5000000 `);`

However, I am getting the `Unable to create resource.` error.

It would be good if you could share your thoughts on this. Is there anything I am doing wrong in implementation, or do you have an example of where I can upload the video to Cloudflare?