Category "back-button"

How to intercept flutter back-button when keyboard is shown

I want to intercept the back-button of the soft keyboard in flutter. So when I want to close the keyboard by pressing the back-button I want an additional funct

How to detect when back button pressed in fragment android?

I have project with navigation drawer with fragment, with 5 menu, the problem is when i go to menu 4 and the i press the back button the app closed, but i need