How to configure relying party trust with Azure AD?

Hi,

I am attempting to configure Azure Active Directory to act as an IDP for an SP initiated SAML flow.  However, there is nowhere to establish the relying part trust...

I see that there used to be a field to declare the SPs "Federation metadata URL", but I don't see that on the application configuration page.  Ref here, about two-thirds down the page - http://www.theidentityguy.com/articles/2013/6/4/a-look-at-azure-ads-web-sign-in-endpoints.html

How do I establish the trust with the SP?

Thanks,

Stuart