I was able to get a Hubspot form working on a Wix site by doing the following:
1. Build a form in Hubspot and export.
2. In a premium Wix site, Add > more > custom embeds > add iframe. Paste in both the embed code AND the URL.
3. Add the code to Settings > Tracking + Anlaytics > New Tool > Custom. I added to the header of the page the form is on.
Hope this helps!
