I want to create a popup menu and customize its size and option to give it a icon and a text. But in the properties of the popup menu i am not able to give it an icon and customize its size. How am i able to do that?
You can add an icon if you enable advanced options. When enabled each menu item shows a container widget, where you can compose other widgets i.e. link button with icon and text.
From there you can also change the size of the icon or whatever widget you put in that container.