Taft L. HubSpot integration is on the pro plan. Which plan are you on?
Doing anything beyond basic read/write tasks isn't possible with the native integration.
If creating contacts in HubSpot is the only use case, the direct integration should suffice, but if you run into other complex integration requirements not supported by the native integration, lmk, I might be able to help.
(Think, how do we handle overwriting a mobile number on a customer contact vs zoominfo number on a prospect contact, etc)