code: public static function sendFortnitePostRequest($endpoint, $access_token, $params = null) {
          $client = new Client();
  
          try {
               $response = $client->post($endpoint, [
                  'json' => $params,
                  'headers' => [
                      'User-Agent' => self::FORTNITE_USER_AGENT,
                      'Authorization' => 'bearer ' . $access_token
                  ]
              ]);
  
              return json_decode($response->getBody()->getContents());      
          } catch (GuzzleException$e) {
              throw $e; //Throw exception back up to caller
          }
  
      }
docs: Sends a POST request as the Fortnite client.
  @param  string $endpoint     API endpoint to request
  @param  string $access_token OAuth2 access token
  @param  array  $params       Request parameters, using the name as the array key and value as the array value
  @return object               Decoded JSON response body