API explorer supporting traffic segmentation will be ready soon. In the meantime, you can use the old API explorer which supports all endpoints, but lack filters. It is available at apiexplorer.contentinsights.com/v1
To use API explorer click on the "Authorize" button on the top right and enter your API key.
Your API key is on the path: Top right corner menu (your initials/photo)>Edit account>API Key: