First navigate to your Account & Billing section from the bottom left menu:

Click on the Subscribe button:

First add your credit card. You are just adding a card to your account, nothing is going to be charged yet. Add your name, card number, expiration and CVC.

Once added click Save New Card:

Now you should see your card added with last 4 numbers displayed. Click on the drop-down on the right to choose your plan:

Check the box next to the plan you want:

Now all that's left is to click Subscribe:

That's it. Welcome to Spotlightr!