HELP - A PROBLEM I CAN NOT SOLVE

Hello you guys,
Would appreciate help
I bought the antivirus, and turned it on, and suddenly I was notified that there was an error or error in the activation code sent to me by email.
I removed the antivirus and reinstalled it, which does not help.
I’m trying to get someone who can help me in the company, without success.
what should I do?

Maybe this will help
https://support.avast.com/en-ca/article/Troubleshoot-activation