In this section, learn how you can configure a flow that automatically creates a new mail merge document and send it via email whenever there is a webhook trigger. A webhook trigger lets you push data from third-party applications to Zoho Flow. Using the custom URL provided by Zoho Flow, you can set up an integration that starts whenever there is a data update in the code or a third-party application. Read more here.

Let's see the steps in detail:

1. Go tohttps://flow.zoho.com and click Create Flow.
2. Enter a name for your flow and click Create. 
3. Choose what should trigger the flow. In this case, choose Webhook. This triggers an action whenever there is a webhook trigger. Click Configure.
4. In the Webhook Trigger panel, choose JSON as your payload format. Click Next.
5. Click Test to test the webhook.
6. Click Done.
7. Now, you need to configure an action for the created trigger. Search for Writer from the Apps panel. Choose 'Create mail merge document' as the trigger and drag and drop in the Flow window.
8. Connect and Authorize your Writer account. Now the list of merged documents will be displayed. Select the required document (already created in your Writer account). Choose the mail type, add an email address, subject, and message body and click Done.
9. The flow between the webhook and Writer is now created. Whenever there is a webhook trigger, the merged documents will be created and sent via mail automatically.