Use a subdomain
a subdomain, depending on your web host can be
as a path example and your host may use folders in the htdocs folder as subdomains or in the yourdomain folder, the subdomain folder. Examples
which technically is outside your htdocs and shouldn't be served but my host allows both methods, in the latter, you set up a virtual path in the control pannel to link to the subdomain that is hidden, the other is accessed when you link the same type of link to a folder in the htdocs folder.
In both cases, your URL would be protocol://subdomain.yourdomain.tld/index.ext
So find out how your host or server deals with subdomains, set one up and upload your test site that can be as fully featured as you wish.