Anyone have experience with connecting a Squarespace form to Hubspot?

Hi folks, 

I was wondering if anyone of you has any experience of connecting a form from Squarespace to Hubspot. 
Client does not want to embed a form from Hubspot into the website, but wants to shoot through the filled in fields to Hubspot. Doesn't want to use Zapier as well. 

Is there another work around? We've added the code from Hubspot into Code Injection as well. 
Anyone who has a solution?