Paid version Internet Security

I've bought via groupon a licence for internet security. Every time when I start the pc (Windows 10) AVG fill in a default license key that is not mine. AVG shows that the key will not be valid after a few days. Because of this I uninstalled AVG so I can reinstall the software again.
After downloading the software, I can not find a button or something like that to activate my key. It only shows a free key that will expire within a few days.

Hi Rinaldo,
We regret to hear about the inconvenience caused. We have sent an email to your registered email address about your query, please check your email and reply back to us with the requested information. Thank you for your understanding.
Please, feel free to let us know if you require any further assistance.

Hi Rinaldo,
We regret to hear about the inconvenience caused. We have sent an email to your registered email address about your query, please check your email and reply back to us with the requested information. Thank you for your understanding.
Please, feel free to let us know if you require any further assistance.