code: func (bot *BotAPI) AnswerPreCheckoutQuery(config PreCheckoutConfig) (APIResponse, error) {
  	v := url.Values{}
  
  	v.Add("pre_checkout_query_id", config.PreCheckoutQueryID)
  	v.Add("ok", strconv.FormatBool(config.OK))
  	if config.OK != true {
  		v.Add("error", config.ErrorMessage)
  	}
  
  	bot.debugLog("answerPreCheckoutQuery", v, nil)
  
  	return bot.MakeRequest("answerPreCheckoutQuery", v)
  }
docs: // AnswerPreCheckoutQuery allows you to reply to Update with pre_checkout_query.