1)

Note: This point is for shared hosting customers!

You can access cPanel from Customer Area (AKA: One Portal)

1. Login to customer area
2. From the navigation menu click on Services > My Services > Click on service name
3. You'll find Login to cPanel link in the sidebar.

2)

You can also access cPanel directly using your domain or server IP in the following way:

https://domain.com:2083 or https://server.ip:2083

where serverip stands for the IP address of the server where your account resides.

Your browser may show a security warning related to SSL certificate when you try to login with the server IP, you can safely ignore this warning.