Use the search module anywhere in the site with a keyword wich should return one of the products from the Test category, for example "tests". If you don't see the Test product then the pludgin works. Is simple than that!
The plugin is a standard J2Store application, installs as any other Joomla plugin and can be managed both from usual plugin area or from the Apps section in the J2Store setup.
If correctly configured, collects and passes to the selected Constant Contact list the first name, last name and email address of the buyer. It is triggered by the onJ2StoreAfterCreateNewOrder event.
The setup is simple, there are 3 parameters to be filled:
You can obtain the Api Key and the Authorization Token you need to register an account at https://constantcontact.mashery.com and link it to your main Constant Contact account.
You can find out your Membership List ID in the same place, in API Tester Tab go to "Retrieve a collection of ContactLists" then click on Try it, It will show you all the existing List IDs.