Enabling First Party serves the HUMAN client and Captcha files from your local domain. This is recommended, as it helps prevent blocking the HUMAN JavaScript files by privacy plugins and ad blockers.
You must let HUMAN Support know that you are configuring the HUMAN Sales Force Commerce Cloud cartridge to handle First Party requests, as there are configurations that need to be made on the backend. If you do not notify Support, your First Party configuration will not work.
After configuring HUMAN within Sales Force Commerce Cloud cartridge to handle First Party requests, complete the steps listed on the Integrate 1st-Party JS Snippet to make sure your snippet is setup to serve the Javascript Sensor via First Party.