Hi @GoodResource • Thank you for reaching out.
Yes, Azure AD SSPR can be used to reset the passwords of Synced Users as well as Cloud-only Users. However, for SSPR to work with Synced Users, you are required to enable Password Writeback in AD connect. It works for user accounts which are synced from local AD to Azure AD with ADFS federation as well.
As shown below you need to configure on-prem integration in Azure Portal as well:
For step-by-step instructions and prerequisites, please refer to Tutorial: Enable Azure Active Directory self-service password reset writeback to an on-premises environment
-----------------------------------------------------------------------------------------------------------
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.