On Thursday last week Apple announced that with the public release of iOS 14.5, iPadOS 14.5, and tvOS 14.5, all apps must use the AppTracking Transparency framework to request the user’s permission to track them.
So, you will be asked by each app if you’d like to be tracked. Do not despair; Google have provided some guidance, best practices and some resources on conversion measurement. So with some changes to your tracking and campaign you are good to go.