To opt out of the oneAudience services, you will need to locate and enter your Advertising ID. This allows us to identify your mobile device and ensure your device is opted out of our services.
For Android devices
Settings // Google Services // Ads // Your Advertising ID
For iOS devices
An easy way to find your device’s IDFA value is to use an app called The Identifiers. After launching the app, you can find your device’s IDFA listed in the middle of the screen.