Confusing 0 (zero) with O (letter) is a common mistake.

To activate these features in the full version, you must enter your product key on the that appears when you first run the game, or by using Ctrl+V to paste it from your clipboard.

Websites offering "free keys" or "cracks" for version 1.6.1 frequently bundle downloads with malicious software. These can include ransomware, trojans, or cryptocurrency miners that compromise your PC's health and personal data. Unstable Gameplay

I can provide specific steps to help you resolve your issues.