I am trying to add a custom B2B App to iTunes connect, from Apples documentation it appears there should be a text box to enter the clients Apple ID, but I don't seem to have anything like that.
Here is what the Apple Documentation looks like Apple Doc
And here is what I see in iTunes Connect Link
How do I add the Apple ID's for the custom B2B Apps distribution ?
You are not crazy and are adding the Apple ID correctly.
Currently there is an issue with Apple's site and it is preventing the adding of apple ID's. The page will just refresh after hitting the "add Apple ID" button.
I have tested this in Chrome, Safari, and Mobile Safari. I even have an open ticket where Apple support verified the issue with their test accounts and mentioned there are 4 other tickets open at the time I called it in.
Unfortunately there isn't anything you can do different. If you haven't already, you should call Apple Support and start a ticket for it so you get notified when it is fixed.
EDIT
It took over two weeks but as of 04-02-2015 iTunes connect has been fixed and you will be able to add Apple IDs for B2B apps.
Hopefully that helps.
来源：https://stackoverflow.com/questions/29079735/how-do-you-add-apple-ids-for-a-custom-b2b-app