Immich configuration (unstable) on stable base config

I have a flake configuration with the stable channel as the main input. I am now trying to install the service immich on my system which is only in the unstable channel.
I therefore have something like this to get the immich service

{ pkgs, inputs, .. }
{
disabledModules = ["services/web-apps/immich.nix"];
imports = ['${inputs.unstable}/nixos/modules/services/web-apps/immich.nix'];

services.immich = {
enable = true;
package = inputs.unstable.immich;  # Problematic Line of Code
};

But I am not sure which package I have to chose to work correctly, as removing the package = … line would otherwise lead to the stable package of immich (which does not exist) and the written configuration results in the error

error: attribute 'immich' missing

i assume you are running x86_64-linux then the right attribute for the immich package should be

inputs.unstable.legacyPackages.x86_64-linux.immich