UHRS is not available for all Clickworkers. 

Assessments “UHRS I” and “UHRS II” will appear in the assessments section if it is available in your country, and, or, for your language skills. 

You must successfully pass both assessments to qualify. In addition, during “UHRS II” you must create an account on live.com. Detailed instructions about the data needed are available in the work instructions of the assessment.