Hello @Miklósik, L (László),
Thank you for posting your query on Microsoft Q&A.
Based on your description, I understand that you are planning to migrate your users from Azure AD B2C to Microsoft Entra External ID.
Microsoft Entra External ID is a new and evolving product, and our engineering team is actively working on streamlining the migration process. Currently, it is in the testing phase.
For updates on its availability, please follow: Microsoft Entra External ID: What's New.
At this time, there is no publicly released migration process, as it remains in the testing phase. Once it is released for public preview, detailed migration steps will be documented.
Please refer below blog post and screenshot for more details: Evolve your CIAM strategy with External ID
I hope this information is helpful. Please feel free to reach out if you have any further questions.
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