setSSLKey example

$clientBuilder->setLogger($logger);

        if ($sslConfig['verify_server_cert'] === false) {
            $clientBuilder->setSSLVerification(false);
        }

        if (isset($sslConfig['cert_path'])) {
            $clientBuilder->setSSLCert($sslConfig['cert_path'], $sslConfig['cert_password'] ?? null);
        }

        if (isset($sslConfig['cert_key_path'])) {
            $clientBuilder->setSSLKey($sslConfig['cert_key_path'], $sslConfig['cert_key_password'] ?? null);
        }

        return $clientBuilder->build();
    }
}