Flutter – Floating Button inside a popup widget overlaying the scroll

Im working on my first flutter app so i am still learning possible widgets and how they react in certain structures.

So far I was doing well but cant figure out one thing I want to do.

I want to get a floating button inside of my cupertinopopusurface widget like this.

My structure is similar, on the home screen I have a listview builder that builds my cards and when you press on each one it opens a cupertinopopupsurface.

Inside I also built a Single child scroll view structure for all my contant and its scrollable but I would to get a button that overlays it all and is in a fixed placed.

My structure currently is

CupertinoPopupSurface/
Container/
SingleChildScrollView/
Column/
Children/
Row/ (all rows now with content)

I cant get the button fixed somewhere in the structure but then it follows the scrolling its now fixed overlaying the contant.

>Solution :

You can use stack widget inside cupertinopopupsurface like this:

CupertinoPopupSurface(
   child: Stack(
      children:[
         your SingleChildScrollView,
         Positioned(left: 16, right: 16, bottom: 16,child: yourbutton),
      ]
    
    )
)