Support
Write to support@whyilost.app in English, Ukrainian or Spanish. Say which iPhone you have, its iOS version and the game's version (the last line of the game's settings), and what happened.
The game's settings open from the gear button, on the first screen, during a run and at its end.
Restore a purchase
Open the full game's page (the locked Sandbox button on the first screen, or THE FULL GAME in settings) or the settings themselves, and tap Restore purchase. Use the Apple Account you bought with.
The full game on another iPhone
Sign in with the same Apple Account, and the game reads the purchase when it starts. If it still reads locked, tap Restore purchase. This purchase is not shared through Family Sharing, so each family member needs their own.
Purchases turned off
If Screen Time or a configuration profile blocks in-app purchases, the full game's page says so and offers only Restore purchase. Change the restriction in Screen Time, or ask whoever manages the iPhone.
Start a new run
In settings, tap Start a new run. The game asks first, because the run in progress is discarded for good. When a run ends, Start a new run is also on the last screen.
Change the language
In settings, tap the language button. Until you choose one, the game follows your iPhone's language when it is English, Ukrainian or Spanish.
Refunds
Refunds are Apple's to grant: ask for one at reportaproblem.apple.com.