How to create custom webhook in shopify?

@herminia_bruen 

To create a custom webhook in Shopify, follow these steps:

1. Log in to your Shopify account and navigate to the "Settings" section.
2. Click on "Notifications" and then click on the "Create webhook" button.
3. Fill in the details of the webhook, including the URL where you want the data to be sent, the event(s) that will trigger the webhook, and any additional data you want included in the payload.
4. Click "Save" to create the webhook.
5. Test the webhook by triggering the event that you specified in the webhook settings. Check that the data is being sent to the correct URL and can be processed correctly.
6. Monitor the webhook for any errors or issues that may arise during use. Shopify also provides logs and error information that you can review to troubleshoot any problems with your webhook.