I have an On-Premise Dynamics 365 on version 9 with my own On-Premise Active Directory and IFD setup. Now I want to federate with an external business so that they can login to my Dynamics 365 On-Premise with their own usernames, but they've only got Azure AD, no On-Premise AD. I've managed to configure ADFS federation with other businesses before but they've had a local ADFS server which I federated with.
Is this possible, and is there any sort of documentation about this out there somewhere?