Hello Rb.cw,
Thanks for your question.
Microsoft only supports provisioning of users from Entra ID to Google.
Inbound provisioning is only supported for HCM apps like Successfactors or workday as Entra ID is the Source of authority for user provisioning in azure.
https://learn.microsoft.com/en-us/entra/identity/app-provisioning/user-provisioning
For a different alternative that doesn't use SCIM provisioning, You can consider federation between Google Workspace and Microsoft Entra ID.
https://learn.microsoft.com/en-us/education/windows/configure-aad-google-trust
Regards.
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