To trigger an instant trigger (Custom webhook module) in your scenario when an event occurs in a web service that is not currently implemented (and supports sending webhooks) as an app in Integromat, please follow these steps:
1. Add the Webhooks > Custom webhook module to your scenario.
2. Set the webhook name, if needed.
3. Copy the provided address to the clipboard.
1. Log in to the web service account.
2. Click on the cog-wheel in the menu on the left to open the settings.
3. Open the Webhooks settings and click the green Create Webhook button.
4. Enter the name for the webhook.
5. Enter the address you have copied to your clipboard in step 3 in the Adding the Instant Trigger (webhook) to Your Scenario section above.
6. Select the event that will trigger the webhook.
Now, run your Integromat scenario with the Webhooks > Custom webhook module. The module (and scenario) is triggered when the specified event in the web service occurs.