If you have one scene, then after opening the game for the first time to test, wait 2 minutes before pushing the "Show Banner" button to display ads.

Don't forget to disable adblock on gamemonetize.com, or else the ad demo will not show, and you will not be able to unlock the "Submit Game" button. After showing the ad demo, hit save.

Don't forget to add a default image (512x384), category, tags, description, and instructions on how to play.

Here is the video on how to Upload your game .zip