See the official installation guidelines at hidable/install

To start using Hidable widget, we have to create a ScrollController. inctance before.

final ScrollController scrollController = ScrollController();

As case of usage, we should have one scrollable widget (SingleChildScrollView, ListView etc) and one static located widget (AppBar, BottomNavigationBar, FloatingActionButton and etc) which would be wrapped with Hidable widget.

So, scrollController which we created before must be given to each one (scrollable widget and static located hidable widget).

ListView.separated(
  // General scroll controller which makes bridge between
  // This ListView and Hidable widget.
  controller: scrollController,
  itemCount: colors.length,
  itemBuilder: (_, i) => Container(
     height: 50,
     color: colors[i].withOpacity(.6),
  ),
  separatorBuilder: (_, __) => const SizedBox(height: 10),
),

Hidable(
  controller: scrollController,
  enableOpacityAnimation: true, // optional, defaults to `true`.
  child: BottomNavigationBar(...),
),

That is the common usage of hidable, and also you can find full code implmenetation of hidable at official example page.