code: func (c *Client) AddTxtRecord(info *Data, fqdn, value string, ttl int) error {
  	id, err := strconv.Atoi(info.ID)
  	if err != nil {
  		return fmt.Errorf("CloudXNS: invalid zone ID: %v", err)
  	}
  
  	payload := TXTRecord{
  		ID:     id,
  		Host:   dns01.UnFqdn(strings.TrimSuffix(fqdn, info.Domain)),
  		Value:  value,
  		Type:   "TXT",
  		LineID: 1,
  		TTL:    ttl,
  	}
  
  	body, err := json.Marshal(payload)
  	if err != nil {
  		return fmt.Errorf("CloudXNS: record unmarshaling error: %v", err)
  	}
  
  	_, err = c.doRequest(http.MethodPost, "record", body)
  	return err
  }
docs: // AddTxtRecord add a TXT record