What HTTP headers are required when using Proxy with Basic authentication?

Question

proxy

$curlClient     = new HttpBrowser(HttpClient::create());

            $response = $curlClient->request('GET', $url, [
                'headers' => [
                    'Proxy' => '10.10.10.10:3128',
                    'Proxy-Authorization' => 'Basic user:pass'
                ],
            ]);