try stalonetray

config/stalonetray/stalonetrayrc

@@ -0,0 +1,16 @@
+decorations none
+transparent false
+dockapp_mode none
+geometry 5x1-400+0
+max_geometry 5x1-325-10
+background "#000000"
+kludges force_icons_size
+grow_gravity NE
+icon_gravity NE
+icon_size 12
+sticky true
+#window_strut none
+window_type dock
+window_layer bottom
+#no_shrink false
+skip_taskbar true

modules/desktop/xmonad/default.nix

@@ -69,6 +69,7 @@ in
       xmobar
       # tray
       trayer
+      stalonetray
     ];
 
     home-manager.users.sako = { pkgs , ...}: {
@@ -90,6 +91,10 @@ in
           enable = true;
           source = ../../../config/background.png;
         };
+        ".stalonetrayrc" = {
+          enable = true;
+          source = ../../../config/stalonetray;
+        };
       };
       xdg.configFile = {
         xmonad = {