`qvm-sync-appmenus` works by invoking *GetAppMenus* [Qubes service](/doc/qrexec/) in the target domain.
This service enumerates installed applications and sends formatted info back to the dom0 script (`/usr/libexec/qubes-appmenus/qubes-receive-appmenus`) which creates .desktop files in the AppVM/TemplateVM directory.
For Linux VMs the service script is in `/etc/qubes-rpc/qubes.GetAppMenus`.
In Windows it's a PowerShell script located in `c:\Program Files\Invisible Things Lab\Qubes OS Windows Tools\qubes-rpc-services\get-appmenus.ps1` by default.
Each menu entry is a file that follows the [.desktop file format](https://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html) with some wildcards (*%VMNAME%*, *%VMDIR%*).
Note that you can create a shortcut that points to a .desktop file in your AppVM with e.g. `qvm-run -q -a --service -- personal qubes.StartApp+firefox`
The list of installed applications for each AppVM is stored in dom0's `/var/lib/qubes/vm-templates/templatename/apps.templates` (or in case of StandaloneVM: `/var/lib/qubes/appvms/vmname/apps.templates`).
Each menu entry is a file that follows the [.desktop file format](https://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html) with some wildcards (*%VMNAME%*, *%VMDIR%*).
Applications selected to appear in the menu are stored in `/var/lib/qubes/appvms/vmname/apps`.
Note that you can create a shortcut that points to a .desktop file in your AppVM with e.g. `qvm-run -q --tray -a personal -- 'qubes-desktop-run /home/user/application.desktop'`.