Log in to the WorldPay CMS
You should now be presented with a screen containing the following:Click Configuration Options next to the Installation which has (Select Junior). This will lead you to the configuration screen which should look like the following:Enter the following URL in the 'Callback URL' field:
https://www.example.com/forums/payment_gateway.php?method=worldpay
Check the Callback enabled checkbox.
Within the 'Callback password' field enter an appropriately secure password, this will be used for verifying transactions.
Click
To set the Installation ID and password Paid Subscriptions > Payment API Manager > Worldpay and enter your Installation ID that was displayed in the initial login to the WorldPay CMS and the password you setup within the CMS.