Flutter showModalBottomSheet below app bar

Question

I try to show modal bottom sheet on google map page but I need the barrier to be below the app bar for using back button. I can't acheive that. Then I thought to replace it with bottom sheet but the map will be enabled and I don't want that.

I need the modal bottom sheet below the app bar and not dismissable ..

Solution

Finally, I found workaround solution with two steps:
1- I used BottomSheet instead of ModalBottomSheet.
2- I add ModalBarrier above the map to disable interactive with it.

In this case appbar still active.

That's all !