how to run external fullscreen exe file on unity ?

hello community,
i want to put button ;when user click it run exe file full screen in my project and when user clicked close in my exe file return to unity project fullscreen . its very important to my project. thanks if anyone help me

I guess you could set your unity program to run in background via player settings, start the exe via Process.Start and wait for it to complete. That executable should know how to set itself up in full screen mode, but you can also set the ProcessStartInfo to start it with a maximized window style (although this isn’t the same thing as full screen mode).

To bring Unity back into full screen mode when the process terminates, try using the Screen class.