Thank you for posting your query on Microsoft Q&A, from above description I could understand that you have a guest account which is synced from on-prem to Entra ID and you would like to enable SSPR for such accounts.
Kindly confirm if this is not the case by responding in the comments section
On-prem AD isn't synced to Azure AD as Guest and those users would be synced as regular user and it's as per design. SSPR would work and could be setup by following: Enable Microsoft Entra self-service password reset writeback to an on-premises environment. This would:
- Configure the required permissions for password writeback
- Enable the password writeback option in Microsoft Entra Connect
- Enable password writeback in Microsoft Entra SSPR
However if you plan to invite the user as Guest to AAD then, as per Password reset for B2B users
Password reset and change are fully supported on all business-to-business (B2B) configurations. B2B user password reset is supported in the following three cases:
- Users from a partner organization with an existing Microsoft Entra tenant
- Users who sign up through self-service sign-up
- B2B users: Any new B2B users created by using the new Microsoft Entra B2B capabilities
However, Microsoft accounts that have been granted guest access to your Microsoft Entra tenant, such as those from Hotmail.com, Outlook.com, or other personal email addresses, aren't able to use Microsoft Entra SSPR. They need to reset their password by using the information found in the When you can't sign in to your Microsoft account article.
Thanks,
Akshay Kaushik
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