Configure: Splunk Webhook Alert
Configure the Webhook on your Splunk server
Open the "Configure Mediator" gear icon to reveal the webhook url

Copy the Url

Open Splunk and Select "Searches, Reports and Alerts"

Press the "Add Alert" button

Create a new alert and select "Webhook" as the target

Tip: For faster searching, add an asterisk to the end of your partial query. Example: cert*