In fact, the domain you’re using is not even registered, that’s why there are no nameservers! Please register it first through a domain registrar of your choice (we recommend Namesilo), then point it to the nameservers, wait some time and then you can finally add it to your hosting account. If you don’t have money to buy that domain, you can also consider to create a hosting account with a subdomain first, or get a free domain from EU.org.
EU.org is the only one I had in mind that allows changing nameservers without making a request to the service’s admins to enable it though, but their domains need a long time to be activated… Sometimes only a week or two, sometimes also one/two months, rarely even more…