Alert with Webhook notification not working


I am trying to test Redash Webhooks and I have set up an alert from a query that just counts some fields and if is greater than 0, alerts (this condition is always true).

The alert has the notifications send to my personal email, and a mock Webhook. At first I just wanted to see if it works and visualize the payload, so I am using the to do so.

When I run the query, I receive an email however I do not receive anything in the I do not have access to the logs nor the Redash installation to verify if there is something wrong.

I would like to know if there is anything that could be possibly preventing this alert to send to the Webhook?

Thanks in advance.