For a computer where After Effects is kept off the internet. Takes about a minute.
In KEYFRAMR, press Copy next to your computer code, then paste it here. It starts with KFC1-
Filled in for you by KEYFRAMR. Paste a different computer code
From your Payhip receipt email
Paste it into KEYFRAMR, in the box under "Paste the switch-on code the page shows", and press Use This Code.