I have purchased webanimator plus. I have the invoice with activation code. How do I put that code into the software to make it work. It is still showing as a 14 day trial version. HELP PLEASE

I purchased for the 2nd time WebAnimator Plus and have my activation code but where do I enter it. The software installed and in the About menu it says it is a a 14 day trial version. . I uninstalled and tied again. Same thing happened. Help please