services.hickory-dns.settings.zones.*.zone_type

One of:

For more details about these zone types, consult the documentation for BIND, though note that hickory-dns supports only a subset of BIND's zone types: https://bind9.readthedocs.io/en/v9_18_4/reference.html#type

Type
one of "Primary", "Secondary", "External"
Default
"Primary"
Declared
<nixpkgs/nixos/modules/services/networking/hickory-dns.nix>