When you first Logging Into the Helm 3 Control Panel, you will need to log in using the login URL located in your Welcome Email.
After you add a domain to the control panel, you can access the control panel by going to http://control.YourDomain.com/
Simply replace <YourDomain.com> with your actual domain name.
When you first get to the Helm Control Panel login screen, you will be prompted to enter your username and password. These will have been given to you in the Welcome Email. Below is the default login page you will see: