Our checkout page can be accessed by clicking on 'Upgrade Subjects' in our Course Library or any subject page. The direct link is: https://www.albert.io/marketplace/subjects
You should see this page...
Select the subjects you would like to upgrade and either 3 or 10 months for the duration of your subscription. Use the left-hand-side sidebar to navigate between courses in the library.
When you have all the courses you want, click 'Continue' at the bottom of the page
Fill in your payment information and click 'Complete Checkout.'
Upgrades last for either 3 or 10 months from the day of purchase.