I have a Catalyst Event function where I can process the incoming data and store them in Datastore. I tried testing it with Zoho Event Listeners where I was able to map it with my Zoho CRM which works fine.
But I need to capture the events from my Zoho Billing Service to capture the Subscription events. I tried using Custom event listeners to create it as webhook but it seems to be very complex setup. Is there any way I can access them from the Catalyst project by default?
Without knowing what you have actually tried in your custom event listener, it will be difficult to assist you on what issue you were facing during development. But nonetheless, Catalyst has a beta feature called Signals, which seems to be a feature enhancement for the Zoho Event Listeners that you were using in your project, which can resolve your query on capturing Zoho Billing events in Catalyst.
Catalyst Signals seems to integrate many Zoho products, such as Billing, Invoice etc., which you can map to an event function to perform your app logic to migrate the subscription event data to Zoho Catalyst Datastore using the Insert Row SDK. You can find the official documentation for the Catalyst Signals here and insert the Row Node SDK method here.