Givenergy won't allow octopus intelligent flux permission

Trying to sign up for intelligent flux. Already have flux. When I go through octopus app sign up process it asks to log into givenergy cloud and then asks for permission. See image. Unfortunately clicking on authorize (sorry for US English) does nothing and so I can't get any further in the process. Presume Givenergy webpage fault?

Have you got multifactor authentication on for the GivEnergy portal? If so might need to turn it off whilst onboarding.

Thank you for your reply. Turning off 2fA gets me further but now I get this:

I've tried to repeat the process a few times to no avail.

Actually when I look at connected services it looks like it has worked. I'll await events