I can't complete ISV registration

Question

I have an Azure account for a business and I'm trying to sign up for ISV, but when I go to finish off the ISV form, it asks me to log in. When I go to login, it says that my domain is in not in the system. We are actively using a variety of Azure services and I am the owner account.

https://www.microsoft.com/en-ca/isv/enroll/signup