Apple has published details on how it plans to deal with all the age verification requirements around the globe and the US. It will be a mixture of age categories and parental controls
Age requirements for apps distributed in Brazil, Australia, Singapore, Utah, and Louisiana - Latest News - Apple Developer
Today we’re providing an update on the tools available for developers to meet their age assurance obligations under upcoming U.S. and regional laws, including in Brazil, Australia, Singapore, Utah, and Louisiana. Updates to the Declared Age Range API are now available in beta for testing.
(developer.apple.com)

