How to set up opt-out for mobile apps?

The opt-out functionality is made available for apps via methods in our SDK explained in this documentation: https://developers.atinternet-solutions.com/piano-analytics/data-collection/how-to-send-events/consent

When the app is launched, you will simply need to give the user the option to opt-out via a dedicated screen. If the user doesn't wish to be tracked, you can then set the consent mode “opt-out“ in the tag to prevent the creation of a client ID (we will instead receive "opt-out").