what you see relates to the quality in the editor! not of the game !
to change the quality of the game is another thing
but nothing difficult!
in blueprint you have to open a function that is called ‘’ execute consol command ‘’
as a string, you must give one of these: Scalability Reference | Unreal Engine Documentation (example: sg.PostProcessQuality 0 or sg.PostProcessQuality 1 ecc)
so, if you make a widget you can use on button press event to fire your function
if you want the widget start before the game : make an empty level for the widget that start on begin play
and make a button that open the first level of your game
Andrea