Associate the Webhook with the Workflow Rule

Follow these steps:

Go to Setup > Automation > Workflow Rules and click Create Rules.
Choose the Module for which you need to create a Workflow rule, then provide the rule name and description.
Select the When condition for the rule to execute. For this example, we are creating a workflow rule which will trigger an automated message to Leads when a lead is created in Zoho CRM.
Select the records to which this rule should be applied.
Select Webhooks in Instant Actions.
Select and associate the Webhook that you created.

The module selected for the Workflow rule and the module selected for the Webhook should be the same.
Click Save to finalize this process and associate the Webhook with the Workflow.