Hello John,
Yes, it is necessary to enter the renewed license number on the program to continue with the subscription.
You should have received the renewed license number to the registered email address.
If it is not found in inbox do check in spam and junk folders.
For activation, open AVG Internet Security interface.
Click on "My AVG" and select "My Subscriptions".
Click on "Enter new license" and enter the renewed license number.
Check whether you are getting the expiry date displayed as 15th May 2020.