code: func (d *DNSProvider) CleanUp(domainName, token, keyAuth string) error {
  	fqdn, value := dns01.GetRecord(domainName, keyAuth)
  
  	zone, err := dns01.FindZoneByFqdn(fqdn)
  	if err != nil {
  		return fmt.Errorf("netcup: failed to find DNSZone, %v", err)
  	}
  
  	sessionID, err := d.client.Login()
  	if err != nil {
  		return fmt.Errorf("netcup: %v", err)
  	}
  
  	defer func() {
  		err = d.client.Logout(sessionID)
  		if err != nil {
  			log.Print("netcup: %v", err)
  		}
  	}()
  
  	hostname := strings.Replace(fqdn, "."+zone, "", 1)
  
  	zone = dns01.UnFqdn(zone)
  
  	records, err := d.client.GetDNSRecords(zone, sessionID)
  	if err != nil {
  		return fmt.Errorf("netcup: %v", err)
  	}
  
  	record := internal.DNSRecord{
  		Hostname:    hostname,
  		RecordType:  "TXT",
  		Destination: value,
  	}
  
  	idx, err := internal.GetDNSRecordIdx(records, record)
  	if err != nil {
  		return fmt.Errorf("netcup: %v", err)
  	}
  
  	records[idx].DeleteRecord = true
  
  	err = d.client.UpdateDNSRecord(sessionID, zone, []internal.DNSRecord{records[idx]})
  	if err != nil {
  		return fmt.Errorf("netcup: %v", err)
  	}
  
  	return nil
  }
docs: // CleanUp removes the TXT record matching the specified parameters