Hi @anilerkan, the Hubspot trigger node would not support private app authentication and you would have to use OAuth2 instead (n8n refers to this as the “HubSpot Developer API” as it also requires a separate developer API token in addition to the regular OAuth2 details.
That said, this is a very cumbersome process in Hubspot when self-hosting n8n (as you’d first need to register as a developer with Hubspot and then register your client application) and I’d suggest avoiding the trigger unless you really need it. Going for a Schedule trigger combined with the regular Hubspot node fetching whatever you want to fetch is often simpler.