The simplest way to test if the WP Shop Cart plugin is working is to create a test product with the price of 1 cent ($0.01) and purchase that product yourself as a buyer.
You can also use the plugin test mode (PayPal Sandbox) which will allow you to test it without having to perform a live transaction. To test it using PayPal Sandbox do the following:
- Go to the WP Shop Cart’s settings menu.
- Enter your sandbox seller’s email in the ‘PayPal Email Address’ field.
- Make “PayPal Test Mode on” to “Yes” from Testing and debugging section.
- Furthermore, enable logging “yes” so you will be able to see every step through the transaction processes (IPN validation, product verification, etc.) in the log file.