As Google Ads' lead form extension does not integrate with Zoho CRM at the moment other than Zapier. I want to use the Zoho Flow webhook feature to send leads to Zoho CRM.

Meaning creating a flow in Zoho Flow that triggers based on Webhook and then webhook data is pushed to Zoho CRM.

The issue I am facing is that Google Ads asks for a "Key" in addition to the "Webhook URL". I am unable to find the key to input in Google Ads. Please guide where to find the "Key" in Zoho Flow?