Changing email address for Login and Billing

Hi, I’ve got cloud edition Manager. I need to change my email for logging in and for my billing information. I have checked previous Forum searches but am having difficulty where I find these.

I login to my portal which gets me to my overview page.

I click on the Update Billing Info tab as below

I get a page with the following:

I click on that to which gets me to the Billing Information page and there is no field for email address (as below).

Seems like the logical process but not getting me anywhere.

As a further point - does this also change my login email as I can’t find anything on this anywhere?