code: public void sendJsonPayload(String json) {
      try {
        this.configReadLock.lock();
        Config config = this.config;
        this.configReadLock.unlock();
  
        sendPayload(config, new Payload(json));
      } catch (Exception e) {
        LOGGER.error("Error while sending payload to Rollbar: {}", e);
      }
    }
docs: Send JSON payload.
  
  @param json the json payload.