Apple stated that all new and updated apps, including those still in testing and basic ones that do not share data in any way, are required to have a privacy policy. The new guidelines came into force on October 3, 2018.
To ensure privacy policies aren’t tweaked after apps have been submitted, Apple also adds that the privacy policy’s link or text cannot be changed until developers submit a new version of their app.
App Store Review Guidelines state that the privacy policy must be available within the app in an “easily accessible manner” and must explain (among other things) which data the app collects, how that data is collected and used, and how a user can delete that data.
You can read more about Privacy Policy for iOS and macOS Apps on our guide to Apple’s App Store Review Guidelines.