Hello,
- How is the existing contact in the CRM paired/matched with Azure AD B2C? Is the email key for that? What would happen in case if there is no match or multiple contacts in the system?
The primary email address is how any authentication is matched to an existing contact.
https://docs.microsoft.com/en-us/powerapps/maker/portals/configure/set-authentication-identity#confirm-an-email-address
If there is no contact, a new contact would be created when the registration setting is turned on. Authentication/Registration/OpenRegistrationEnabled set to true would be required.
If that setting is false and no contact exists, the authentication would fail.
https://docs.microsoft.com/en-us/powerapps/maker/portals/configure/configure-portal-authentication
- Are web roles automatically assigned?
Web roles are not automatically assigned. You need to create a workflow to perform that action if you want to automate the process.
- Is it possible to modify the registration page in a way that it copies values such as VAT, company name, country, etc. to the CRM contact? We would like to have different fields in case of Partner than a Customer support portal.
Each portal will have individual settings and configurations. You can map fields to the contact using claims mapping.
https://docs.microsoft.com/en-us/powerapps/maker/portals/configure/azure-ad-b2c#claims-mapping
- Is it possible to have B2B and B2C available together? We would implement Partner and Customer portal on the same platform and split these two by multibrand portal structure. Or can we use B2C also for partners?
Yes, you can have more than one external authentication configured.
Both portals can be connected to the same environment. Each would have its own URL and landing page (Home page). You could put a link on one of the Home pages for the other portal.
I hope the information provided answered your questions. Portal external authentication is complex and I would recommend opening a support case if you need assistance.
Thanks,
Mark Biggerstaff
Dynamics Support
