Great HMAC Hash and Send with Signature

private function sendWebhook( License $license )
    {
        $webhook = $license->webhook->url;
        $payload = json_encode([
            'license' => $license->key,
            'expires_at' => $license->expires_at,
            'customer' => $license->customer,
        ], JSON_THROW_ON_ERROR);

        $hash = hash_hmac('sha256', $payload, $license->webhook->secret);

        Http::withHeaders([
            'Content-Type' => 'application/json',
            'signature' => $hash
        ])->post($webhook, $payload);
    }