code: func (d *DNSProvider) updateTxtRecord(fqdn, token, txt string, clear bool) error {
  	u, _ := url.Parse("https://www.do.de/api/letsencrypt")
  
  	query := u.Query()
  	query.Set("token", token)
  	query.Set("domain", dns01.UnFqdn(fqdn))
  
  	// api call differs per set/delete
  	if clear {
  		query.Set("action", "delete")
  	} else {
  		query.Set("value", txt)
  	}
  
  	u.RawQuery = query.Encode()
  
  	response, err := d.config.HTTPClient.Get(u.String())
  	if err != nil {
  		return err
  	}
  	defer response.Body.Close()
  
  	bodyBytes, err := ioutil.ReadAll(response.Body)
  	if err != nil {
  		return err
  	}
  
  	var r apiResponse
  	err = json.Unmarshal(bodyBytes, &r)
  	if err != nil {
  		return fmt.Errorf("request to change TXT record for do.de returned the following invalid json (%s); used url [%s]", string(bodyBytes), u)
  	}
  
  	body := string(bodyBytes)
  	if !r.Success {
  		return fmt.Errorf("request to change TXT record for do.de returned the following error result (%s); used url [%s]", body, u)
  	}
  	return nil
  }
docs: // updateTxtRecord Update the domains TXT record
  // To update the TXT record we just need to make one simple get request.