secondaryNavigation property
The slot placed on the end side of the app window.
The end side means the right when the ambient Directionality is TextDirection.ltr and on the left when it is TextDirection.rtl.
If the content is a flexibly sized Widget like Container, wrap the content in a SizedBox or limit its size (width and height) by another method. See the builder in AdaptiveScaffold.standardNavigationRail for an example.
Implementation
final SlotLayout? secondaryNavigation;