Not displaying on main monitor

So what worked for me was to use steams big picture mode, then go to settings (in big picture mode) go to display, resolution, then change the target monitor. When I opened Apex from big pic mode, after changing that setting it opened on the correct monitor. I hear that you can also open the game in borderless window mode and press 'windows key' + shift + right arrow, or left arrow. I have not tried this myself.