Yes, as we will need domain name to setup any hosting plan you choose. We do not offer subdomain hosting.
If you don’t have domain name yet you can register one with us here
If you choose to buy your domain name at another domain registrar, you need to make sure you have login access at that registrar to manually modify your DNS to our servers.
If you already have a domain name, just enter that when you signup, & make sure you can access the settings to modify your DNS settings.