Thank you for the feedback, we will update the documentation with the missing parts. Some ACEs available in the beta will not yet be added, as we have a policy of not adding features to the documentation until they are included in a stable release.
The documentation does include a mention that the privacy policy is required during the guide section, as well as a brief description of "Is configured" but not in the description for the property. Which will be resolved.
Before using adverts inside your game you need to specify your application ID, publisher ID and a privacy policy URL on the Mobile Advert object. Without these values the plugin will not be able to start. If you do not have a privacy policy yet then you can place a filler website address in it's place, but this should be replaced with your actual privacy policy before you release your game.
The plugin will be automatically be configured and ready to go as soon as your game starts. You may want to check the "Is configured" condition in your game to see if configuration failed for any reason; such as being on an invalid platform or one of your properties being incorrect.