samba - Aug 2018 - Proper way of creating a child zone

Hi,

Let's say my domain is example.com, I've created using DNS Manager on
Windows a child testing.example.com, but from samba-tool I cannot delete
it. In fact, it not listed as a zone:

samba-tool dns zonelist 192.168.50.40 -U Administrator
Password for [example\Administrator]:
  2 zone(s) found

  pszZoneName                 : example.com
  Flags                       : DNS_RPC_ZONE_DSINTEGRATED
DNS_RPC_ZONE_UPDATE_SECURE
  ZoneType                    : DNS_ZONE_TYPE_PRIMARY
  Version                     : 50
  dwDpFlags                   : DNS_DP_AUTOCREATED DNS_DP_DOMAIN_DEFAULT
DNS_DP_ENLISTED
  pszDpFqdn                   : DomainDnsZones.example.com

  pszZoneName                 : _msdcs.example.com
  Flags                       : DNS_RPC_ZONE_DSINTEGRATED
DNS_RPC_ZONE_UPDATE_SECURE
  ZoneType                    : DNS_ZONE_TYPE_PRIMARY
  Version                     : 50
  dwDpFlags                   : DNS_DP_AUTOCREATED DNS_DP_FOREST_DEFAULT
DNS_DP_ENLISTED
  pszDpFqdn                   : ForestDnsZones.example.com

I can create RR below testing.example.com but I wonder if is the proper
way. Should I create glue records?  What do you think?
FYI I use SAMBA4 internal DNS.

Thanks in advance
-- 
--
Sergio Belkin
LPIC-2 Certified - http://www.lpi.org