// config/subscribd.php
'gateways' => [
    'paddle' => [
        'driver'         => \Pixelworxio\Subscribd\Gateways\PaddleGateway::class,
        'api_key'        => env('PADDLE_API_KEY'),
        'webhook_secret' => env('PADDLE_WEBHOOK_SECRET'),
        'sandbox'        => env('PADDLE_SANDBOX', false),
        'checkout' => [
            'success_url' => env('PADDLE_SUCCESS_URL'),
            'cancel_url'  => env('PADDLE_CANCEL_URL'),
        ],
    ],
],

PADDLE_API_KEY=...
PADDLE_WEBHOOK_SECRET=...
PADDLE_SANDBOX=false
PADDLE_SUCCESS_URL=https://yourapp.com/billing/success
PADDLE_CANCEL_URL=https://yourapp.com/billing/cancel

use Pixelworxio\Subscribd\Actions\CreateSubscription;

$subscription = app(CreateSubscription::class)->execute($user, $plan, ['gateway' => 'paddle']);

if ($subscription->status->value === 'incomplete') {
    return redirect($subscription->meta['checkout_url']);
}