Auth0\SDK\API\Authentication::impersonate PHP Method

    public function impersonate($user_id, $protocol, $impersonator_id, $client_id, $additionalParameters = [])
    {
        $data = ['protocol' => $protocol, 'impersonator_id' => $impersonator_id, 'client_id' => $client_id, 'additionalParameters' => $additionalParameters];
        return $this->apiClient->post()->users($user_id)->impersonate()->withHeader(new ContentType('application/json'))->withHeader(new AuthorizationBearer($this->access_token['access_token']))->withBody(json_encode($data))->call();
    }

 public function testImpersonation()
 {
     $env = $this->getEnv();
     $api = new Authentication($env['DOMAIN'], $env['GLOBAL_CLIENT_ID'], $env['GLOBAL_CLIENT_SECRET']);
     $url = $api->impersonate('facebook|1434903327', "oauth2", 'auth0|56b110b8d9d327e705e1d2da', 'ycynBrUeQUnFqNacG3GAsaTyDhG4h0qT', ["response_type" => "code"]);
     $this->assertStringStartsWith("https://" . $env['DOMAIN'], $url);
 }