Official comment
Thanks for your request! We'll keep this open to see if others also want a native integration.
There are two alternate methods to use Typeform with ONTRAPORT:
You could use Zapier with Typeform to create or update a contact in ONTRAPORT. That's much easier to do than the second option below.
Typeform does have the ability to use webhooks, and ONTRAPORT could receive the data to add or update a Contact accordingly. This would probably take a developer to set up, but would give more flexibility.