If you want to Edit Records By using Edit Icon follow the below steps:

Step-1:First open the Screen, Where you want to Edit records by using Edit Icon.

Step-2:Next add edit icon on to the gallery.

Step-3:Now paste the below code on Icon.

Navigate(Screen6,ScreenTransition.Fade);Set(Varselecteditem,ThisItem);

Where,

Screen 6:Screen 6 is a navigation Screen,After click on Edit Icon.

Step-4:Next create another screen for to edit record.Once you click on Edit icon the icon directly Navigate to the edit screen.

Hope this Helpful!