Auth0 User Invitation w/ Enterprise Connection and UserId


I would like to support the following use case and am having trouble understanding how to accomplish this with Auth0. I have a server side .net mvc application. This application has a customizable permission feature that allows the administrator custom permissions for their users. There is also a group/role concept but again that is up to the administrator of the tenant. I need to be able to allow the administrator to create/invite a user and at the same time setup their permissions in my application. This data in stored in my backend database. The integration with auth0 from an authentication perspective, in general works however doing an invite to a user that is expected to login from an enterprise connection (Azure AD or Generic OpenId) means I don’t get a userid that I use in my database until AFTER the user has accepted the invitation and logged in. How do I “create” a user in auth0 and get a userid that I can use and save in my database along with their granular permissions prior to the user accepting the invite?