How do I redirect one domain to another domain name?
There are few ways to redirect one domain to another:
Using Redirects in cPanel
PHP or HTML redirects
You can also redirect your domains by creating PHP or HTML index file in the document root folder of your domain. This article provides examples for both programing languages that will help you to complete that redirection.
Using CNAME DNS records
This DNS method will allow you to redirect your subdomains to other domains/subdomains (example: test.yourdomain.com to yourdomain.com).
You can manage CNAME records in the Sample/Advanced DNS Zone Editor in cPanel as long as your domain is pointed to your SiteGround hosting account.