To add a comment/note to a HubSpot deal in Clay, you should use the "Create object" action with HubSpot. Select "Note" as the object type and include the necessary properties like note body and associations to the deal.
Since you're experiencing issues, please copy and paste the JSON you're using so I can help troubleshoot the specific formatting problem.
It looks like clay integration with hubspot is very limited and you’re asking me to provide you a link to hubspot api documentation I’m paying $800/month for to Clay
Hey just heard from Sayli that she just addressed this issue for you, so will merge this thread with hers to avoid back and forth across multiple lines
How can I add comment on a hubspot deal via clay? | Clay