When you want to add a new domain to your WordPress website, you’ll have to go through the WP Engine User Portal. You can’t add domains to multiple environments at the same time, such as multiple WP Engine accounts. When you try to add a domain to one environment, you’ll receive an error message. To resolve this, you should contact a qualified WordPress developer. For more information, see the article: How to Add a Domain to WordPress
Once you have your domain, you’ll have to map it to a specific page within your WordPress installation. If you have more than one domain, you can map them using Alias redirection. You can add several domains to a single WordPress installation using the Alias redirection method. This method works well if you have multiple subdomains or multiple pages. Once you’ve mapped a domain, you can use the Alias redirection option to redirect visitors to the right page.
Changing the domain on your WordPress installation involves several steps, and the correct implementation will ensure that you’re getting maximum SEO benefits. Follow best practices to ensure that your website will be ranked highly in search engines after the domain change. Doing the steps manually will require you to set up your nameservers. Do not worry, though, because the process isn’t too difficult. The tools provided by most hosts will help you to install WordPress without any difficulty.