How to Access Nvidia Overlay with GeForce Experience (2020)

Launch your game. Since an overlay is intended to display on top of another full-screen program, you'll need to be running one in order to activate the overlay feature.

Press and hold Alt+Z. If you don't see an overlay, you'll need to open the GeForce Experience application in the background and click the green Share button on the left side of Settings. You can download GeForce Experience from https://www.nvidia.com/en-us/geforce/geforce-experience/download/.

Release the keys when you see the overlay appear. You can click buttons in the options to take a screenshot, record video, and broadcast your game live to Twitch using the overlay in NVIDIA Share.