The connector from Power Automate to Hubspot is not reliable in my experience. Fortunately Power Automate allows us to build a HTTP request from scratch.

To do this you need a Hubspot API key.

In Power Automate choose the HTTP step:

This is how to set it up for a POST request to add a contact to Hubspot:

Note you have to write “Bearer ” and then the API key.

Note also that attributes in the body are lower case.