services.hostapd.radios.<name>.networks

This defines a BSS, colloquially known as a WiFi network. You have to specify at least one.

Type
attribute set of (submodule)
Default
{ }
Example
{
  wlp2s0 = {
    ssid = "Primary advertised network";
    authentication.saePasswords = [{ passwordFile = "/run/secrets/my-password"; }];
  };
  wlp2s0-1 = {
    ssid = "Secondary advertised network (Open)";
    authentication.mode = "none";
  };
}
Declared
<nixpkgs/nixos/modules/services/networking/hostapd.nix>