Need to apply license number received in email from avg to my mac

Ben, AVG Anti-Virus for Mac is Free. Have a look @ this webpage (http://www.avg.com/ww-en/for-mac). There is no 'paid-for license' version. Also have a look @ this article (http://avgclick.me/1DNofWh).
AVG Guru

I received an account renewal email from AVG advising me to:   

1)Open AVG
2)Click on SUPPORT in the top menu, then REACTIVATE
3)Enter your license number and select ACTIVATE

Here is the problem.  My AVG account previously was on a PC, now discarded.  I now am on a Mac, althouth I never transferred AVG coverage to this computer.  I downloaded the free Mac version to this machine, but there is no button or prompt to REACTIVATE, nowhere to enter my new license number.  How do I proceed?  Thank you.

Ben, AVG Anti-Virus for Mac is Free. Have a look @ this webpage (http://www.avg.com/ww-en/for-mac). There is no 'paid-for license' version. Also have a look @ this article (http://avgclick.me/1DNofWh).
AVG Guru