fix nixos module

flake.nix

@@ -37,8 +37,9 @@
         };
 
         defaultPackage = packages.cohost-blogger;
-
-        nixosModule = { config, lib, pkgs, ... }:
+  }) // {
+    nixosModules = {
+      cohost-blogger = { config, lib, pkgs, ... }:
       with lib;
       let
         cfg = config.services.cohost-blogger;
@@ -57,7 +58,7 @@
           };
           package = mkOption {
             type = types.package;
-              default = self.packages.${system}.default;
+            default = self.defaultPackage.${pkgs.system};
           };
         };
 
@@ -66,7 +67,7 @@
             wantedBy = [ "multi-user.target" ];
 
             environment = {
-                PORT = cfg.port;
+              PORT = toString cfg.port;
             };
 
             serviceConfig = {
@@ -82,16 +83,17 @@
             };
           };
 
-            services.nginx = mkIf cfg.domain {
+          services.nginx = mkIf (cfg.domain != null) {
             virtualHosts."${cfg.domain}" = {
               enableACME = true;
               forceSSL = true;
               locations."/" = {
-                  proxyPass = "http://127.0.0.1:${cfg.port}/";
+                proxyPass = "http://127.0.0.1:${toString cfg.port}/";
+              };
+            };
           };
         };
       };
     };
   };
-  });
 }