After you purchase a new license, it's not automatically applied to a website on your account, and you would need to apply it. This is done to give you flexibility to select which website gets what license:
Step 1: After purchasing the license, open the website you want to apply the license to. Click on Modify License & that will open a page with all plans available to you:

Step 2: Here, you can select the purchased License & click on Select. Doing this will apply that license to your website:
If a specific license is not purchased, you'll have the option to buy that license from this page.

Alternatively, you can go to the Billings & Account Page and modify licenses in bulk across your account via the Modify Site Licenses option:

Was this article helpful?
That’s Great!
Thank you for your feedback
Sorry! We couldn't be helpful
Thank you for your feedback
Feedback sent
We appreciate your effort and will try to fix the article