There is a favourite button in Systray; we can click the button.
Type the menu name in the displayed search box and click the adjacent search button.
Related menus can be seen in the drop-down list. Select the required menu from the list.
The menu button is added to the systray. We can remove the button from the systray by clicking 'X' on the button.
When we click the Search Bar, we can see the view
Systray Menu Favourites
Available in Odoo 18.0 Community and Enterprise.