Laravel passport with pusher: private channel authentication using react native

I want to setup a private channel with pusher for broadcasting events between my laravel app and my react native app.

I'm using laravel passport for the oauth server.

And here is what I have implemented:

react native pusher channel subscription:

let token = 'oauthUserToken';

    var pusher = new Pusher('pusher_key', {
        authEndpoint: 'http://url.com/broadcasting/auth',
        auth: {
            headers: {
                'Accept': 'application/json',
                'Authorization': 'Bearer ' + token
            }
        },
        cluster: 'ap1',
        encrypted: true
    });

var channel = pusher.subscribe('private-hello');

Event class:

class HelloPusher implements ShouldBroadcast
{
    use Dispatchable, InteractsWithSockets, SerializesModels;

    public $message;

    public function __construct($message)
    {
        $this->message = $message;
    }

    public function broadcastOn()
    {
        return new PrivateChannel('hello');
    }
}

routes/channels.php:

Broadcast::channel('hello', function () {
    return true;
});

BroadcastingServiceProvider is commented out in the config/app.php.

And I keep having Pusher : Couldn't get auth info from your webapp : 500.

When I use laravel Echo and Vue on the webapp, private channel subscription is working properly.

I believe it is related to the fact the Broadcast event can't find any user logged in. Any way to use the oauth authorization from laravel passport instead?

Thank you