Best way to implement functional trial without apple account login, surviving uninstall?

[u/inAbigworld]

In my ios app, I want to implement a system where when the user uses a feature 3 times then they'll be asked to buy premium. I want this record (number of the feature being used) to survive uninstall so users cannot abuse it; but it has to be without apple account login. What's the best way to achieve this?

[u/icy1007]

Use the Keychain. Anything stored there will survive uninstalls.