public function register($email, $cellphone, $countryCode, $sendInstallLink = true): Response
    {
        // Prepare required variables
        $url = $this->api.'users/new';
        $params = $this->params + [
            'form_params' => [
                'send_install_link_via_sms' => (bool) $sendInstallLink,
                'user' => [
                    'email' => $email,
                    'cellphone' => preg_replace('/[^0-9]/', '', $cellphone),
                    'country_code' => $countryCode,
                ],
            ],
        ];

        // Register Authy user, and return response
        return new Response($this->http->post($url, $params));
    }