This Domain is not supported or is already registered with Zoho

This Domain is not supported or is already registered with Zoho

hi, at first i try to register to zoho using edtamcn.com, when i step into sms verification phase, my computer got shutdown suddenly, and i have to restart my pc. I have the verification code but i don't know where to put it. So i try to restart the process from beginning, but when i tried to insert the same edtamcn.com to the column, i got warning message like this : "This Domain is not supported or is already registered with Zoho" .

I have submit ticket to support@zohomail.com but with no reply

the edtamcn.com is a new site, and i own that domain. Can you help?