Currently we can only support Google+ brand pages and not profiles, communities, etc. So, please make sure that the Google account, you’re providing the details for, does have a G+ Page linked to it. Otherwise we won’t be able to pull through any relevant pages to populate this dropdown.
If you’re unsure whether the page, you’re looking to add, is a page or a profile, the easiest way to check this is by looking at the screen and, where the profile image is displayed, if there is a +1 count, what you’re looking at is a Personal Profile as opposed to a Google+ Brand Page.
Brand Pages should also display things such as a location map, contact details, etc. to represent the brand.
If you’re still unsure, feel free to send the URL for the page you’re looking to add to firstname.lastname@example.org and
we’ll be happy to check.