Mosquitto bridge config

Hello Nixers,
I’m trying to configure a simple bridge from an MQTT broker (embedded in a Victron GX device) to a NixOS homeserver since Home Assistant support a single MQTT broker configured and I need another to manage some Shelly Flood devices (where HA integration fails to remain connected), merging topics between the Victron broker and mine with the Shelly’s.

From the wiki I see how to configure the broker/listener part, nixos-rebuild succeed, but I can’t understand how to configure the bridge. In mosquitto terms the config is a very simple

connection bridge-hsrv-victron
topic # both 0

but I fails to understand how to write in nix langue the same. From NixOS option mosquitto.bridges is an attribute set of (submodule) so I understand it should be declared like

mosquitto = {
  bridges = {
  };  # bridges
}; # mosquitto

then I need a bridge <name> so I suppose something like

bridges = {
  "bridge-hsrv-victron" = ...
};  # bridges


bridges.bridge-hsrv-victron = {
};  # bridges.bridge-hsrv-victron

imaging it map to the connection mosquitto config directive but I can’t understand the meaning of addresses.*.address, I know I can have many bridges, but if I’m declare one, anything should be in that scope, so I’ve blindly try

addresses.victron = [
  address = "";
  port = "1883";
]; # addresses

but nixos-rebuild fails with error: syntax error, unexpected '=' on

address = "";

And… Well… I can’t understand the logic. Can anyone address me?