Open Domain Management
Go to Domain Management from the left sidebar.
Enter Custom Domain
Enter a custom domain that belongs to an authorized root domain.
Add Domain
Click Add Domain.
Add DNS A Record
In your DNS provider, add:
Type: A
Host / Name: Custom domain
IP Address: To the specified IP
Verify DNS
Click Check DNS in Actions column.
Activate Domain
After successful verification, click Update in Action Column to start using the domain.