This article applies to websites hosted on our newer https://cp.blacknighthosting.com platform.
For how to add extra websites or domains on cp.blacknight.com please see here: https://help.blacknight.com/hc/en-us/articles/212522909
You can only add an extra domain (with its own website) to your plan if you have a Giga or Tera plan. Our Mega and Wordpress plans are limited to one domain per plan.
If you want to set up an alias\forwarder to your main domain instead please see here:
Log in to your https://cp.blacknighthosting.com account and go to:
Sevices > My Services > Click on your Giga or Tera plan (not on the domain name itself) > Addon Domains > Create Addon Domain
Put in your new domain here, pick the Website Hosting option (if you want a forwarder we recommend you create a Domain Alias instead for most cases), and set the document root to where you want to upload the files - we typically recommend you leave it as the default.
Pick the PHP version you want the new domain to use under Other (we recommend the highest PHP-FPM version)
You can then add the domain for email hosting, click on your Titan plan and click 'Sync Hosting Domains'.