No Validate button found when trying to create ZB code to add my existing domain to Zoho email hosting

No Validate button found when trying to create ZB code to add my existing domain to Zoho email hosting

I went to this site https://mail.zoho.com/biz/index.do#

and selected "Add your existing domain for Email Hosting with Zoho and create domain-based address. Add domain"

When I got to the next page https://mail.zoho.com/cpanel/index.do?tabmode=domain there is suppose to be a verify button so I can get the zb code to put into my Network Solutions management counsel and direct the domain to zoho.

the problem is there is no verify button.

Any ideas how to solve this?