Well, basically there are a few things to do, for example, what type of variable is best to use for your case, global or context variable.
Anyway, in my example I use global variable, if it doesn't work for your case, let me know.
Therefore, in the OnStart property of the App I defined the following variables:
/*
The gblReset variable is for resetting the option control to its original state, ie, no choice. Strangely, variables that are used to reset a control, Power Apps doesn't seem to take it well, that's why I set the variable first to false and then to true, as the initial state of the control is unselected.
*/
Set(gblReset, false);
Set(gblReset, true);
// The gblShowPopUp variable is for defining whether the popup is visible or not.
Set(gblShowPopUp, false);
In the Reset property of the selection control, place the gblReset variable:
In the OnSelect property of the selection control, set the gblShowPopUp variable to true:
From there, in your popup, set the Visible property to the gblShowPopUp variable:
In the OnSelect property of the NO button, set:
Notice that we defined the variables again...
On the Yes button, in the OnSelect property, proceed with what your App should do...
Final result:
