He tried another site, one with a comment section filled with "Thank you!" and "Works perfectly!" from accounts with generic names like User992. He followed the instructions: Disable your firewall. Run as administrator.
Instead of searching for a free serial key, consider the following alternatives:
Are you looking to create a or an animated intro ?
Elias looked back at his logo. Was a clean "E" worth the risk of a bricked laptop?
If you’re a student, teacher, or part of a charity, contact the developer directly. Many small software companies donate licenses upon request.