Providing the required tax registration to Intuit

I received an email from notify@quickbase.com back in April. They required confirmation of my registration with the Revenue. I wasn’t registered at that point as I’d only just started by business. The email provided a link for a ‘secure portal’ where I could upload the requested information. When I click on the link, it takes me to Intuit Enterprise SSO and requires my Corporate User ID. I can log into Intuit but not this Enterprise SSO. I’m going round in circles! I said I had a SSO login but it didn’t accept my details. I said I didn’t have a SSO login, expecting it to allow me to set one up but I didn’t get this option. I clicked on forgotten password but don’t receive the emails. I’m at a complete loss as to how I get the required information across to them. Can anyone help please?

Thank you in advance.