What I want to achieve: I want to call HS Form API from my front end, with a custom non-hubspot form.
https://developers.hubspot.com/docs/methods/forms/submit_form_v3 I think has poor documentation in terms of example POST.
What is the URL for posting this data?
Where do I find the Portal ID?
Where do I find the Form ID?
What is the proper payload structure of sending data?
Do I need to make my request a query string on the URL?
Most importantly, can someone show an example of vanilla JS version of posting to Form API with CORS? Data et all please