you can create a launcher that allows to change the settings of the graphics before opening it?
Unreal Engine doesn't allow this unfortunately.
If the game won't even run for you, it's most likely not because your PC doesn't meet the graphical requirements actually, you might be missing some other requirements that are free and easy to install:
If it doesn't run, you may need to install (most PCs should already have them though):
- DirectX End-User Runtime
- Visual C++ Redistributable