To buy the Licence upgrade click on the Buy a One Year Licence Upgrade.
Your Internet browser will be started and you will be taken to a shopping cart page where you can pay for the upgrade using any standard Debit, Credit Card or a PayPal account.
You don’t need a PayPal account! The first screen you will see asks you to “Log in to PayPal” by entering an email address, but it’s actually just asking for your email address so it can send you a receipt for the payment. To proceed, enter your email address and select “Next”.