How to overlay widget on top of the flutter app with getx Route. ( show border and dialog to all screen while screen share)

Question

i want to show screen sharing ui (overlay widget) in my flutter app.

here is steps.

1. user click on screen share button
2. need to show red border and dialog with options
3. need this for all screen while navigate.

here is output i want

for implement this i follow this answer but it not work for me..