You may need to set up a wildcard subdomain, and this can be done within your cPanel account. A wildcard DNS record is a record that matches requests for non-existent domain names. A wildcard DNS record is specified by using the * symbol to create a record for the *.example.com. The most common applications for a wildcard subdomain is for use with SSL or WordPress Multisite.

How to Create a WildCard Subdomain

Congratulations! You have now successfully set up your account for wildcard domains. You still may need to modify your .htaccess file. If you have set up wildcard subdomains for WordPress Multisite, it will automatically configure the .htaccess file for you.