Hi Roei,
More information would be necessary, perhaps screenshots of what you are trying to do. I recommend performing tests using Postman after following the API documentation.
The correct URL to explore the available APIs is:
Documentation:
https://techdocs.broadcom.com/us/en/ca-enterprise-software/business-management/clarity-project-and-portfolio-management-ppm-on-premise/16-1-2/reference/Clarity-REST-APIs/rest-api-documentation-for-authorized-developers.html