Log in to the GenieACS Web UI: using your administrator credentials. 
Navigate to the Configuration Section: by clicking on Admin and then Config in the top menu. 
Add a New Configuration Key: for the authentication parameters. 
Enter the Key: cwmp.connectionRequestAuth. 
Set the Value: to AUTH("yourUsername", "yourPassword"). 
Replace "yourUsername" with the desired username for CPE authentication. 
Replace "yourPassword" with the password the ACS will use to connect to the CPE.