Hello rubyjill1,
If the domain is pointed to our Nameservers and DNS has propagated (4-24 hours after pointing the domain to our Nameservers), the FTP site URL (FTP Host) will be the domain name. If the domain has either not been pointed to our Namesevers or DNS has not propagated, then you can use the server name as the FTP site URL. Your server name is listed as the host name in your account's technical details in AMP.
Please let us know if you have any additional questions or need further assistance.
Regards,
Christi N.