I have no clue what all of you were talking about.
For anyone in the future, here’s the solution (a little inspired by the last reply).
It’s very simple.
GEngine->GameViewport->GetWindow()->Minimize();
that’s the function, simple, here are the includes
#include "Engine/Engine.h"
#include "Engine/GameViewportClient.h"
#include "Widgets/SWindow.h"
Don’t forget to add the new module as Pelogetan said.
KKNich with the clutch