Click on Billing and Subscriptions and then on My Subscription

On top of your window, you will find your current subscription plan and how many products you can import, the transaction fee per product sold, stores available, etc. 

If you scroll down you will also see all our paid plans. 

Choose the one you want by clicking on SUBSCRIBE NOW or even pick a custom plan.

And that's all. You have just picked your subscription plan on AppScenic