When a user consume a serial ; that plugin can perform a special action and add a product into the user cart.
Thanks to the setting "Block product" you can make the selected product impossible to buy except when using a serial.

Parameters of the plugin

Name - The name for the generator. This name is only display in the backend and users won't see it.

Published - Does the generator could be use, or not.

Pack - The related pack that the consumer plugin will deal with.

Product ID - The product that you want to add in the user cart.

Block product - Indicate if you want to forbidden the sale of that product to users without the appropriate serial
That setting requires the plugin HikaShop Product Add Check to work properly.