In general, Webhooks allow web applications to communicate with each other to send real-time data from one application to another whenever a specific event happens.
In this case, your webshop is communicating with the eCredits System and vice versa. Whenever a customer checks out of your webshop using ECS, the eCredits System will notify your webshop if the transaction was successful. Therefore it’s very important to set up the webhook.
If you are not familiar with this, you may want to consult a technician or programmer of your choice to help you set up and properly configure your webshop.