How to find your App ID:
iOS: Open the app entry in Appstore connect and look for the "General Information" in the App information Tab. Your App ID is displayed under the "Apple ID" entry
Android: Open the app entry in the Google Play console and look for the "Information" Symbol in the top right corner of the page. Hover or click on the symbol to display the ID of your Android App. Please note that displaying the ID requires an existing app entry.