Help with Monetization

Let’s say I was about to post a game to Google Play Store or Apple App Store and I want to have In-App Purchases so what is the percentage of the profit to give to Unreal or one of the stores and all I need to add to my game for Unreal not to sue me. Thanks!

Under the EULA, the royalty applies to 5% of all gross revenue, regardless of source (including in-app purchases).

Thank you.