Getting Invalid URL error on Hosted PayPages in the Response Method section

I am using Craft Commerce 3 which provides a webhook endpoint to process Payment Gateway responses, such as the response returning from HPP.  However, when entering the webhook URL into the Approved and Declined URLs in HPP, I get an error message stating that the URL is invalid so I am unable to process any responses from Moneris.

The URL in question looks like this (obvs with the host name removed):  https://[server name here]/index.php?p=actions/commerce/webhooks/process-webhook&gateway=1

Actual error message:

Invalid Approved URL. Please specify a proper URL.
Invalid Declined URL. Please specify a proper URL.