Quality Clouds gets a 401 http response code from ServiceNow when trying to connect to instances with active SSO.
This is the case even if you are connecting as an administrator user, and if your user is not set up to use local authentication but trying to get authenticated with an SSO system.
Make sure that the user which you have configured for Quality Clouds uses local authentication, and is able to use the REST API.
Visit the Quality Clouds Documentation to learn how to set up your Quality Clouds Environment for ServiceNow.