To verify ownership of your domain with some providers, they will ask you to insert a code as an HTML page. To do this, you can upload an HTML document to your httpdocs folder.
To access this document for testing, you can visit <domain>.<TLD>\code.html
This page should be a blank white page, and depending on the verifying body, they may want the code on that page in plain text as well.
This works for portal installations as well, in the same HTTPDOCS location.