Is there a way we can migrate the users from a B2C AD to a second B2C AD.
Can they be copied or synchronised?
You can use the Graph API to move/copy users between Azure AD B2C directories. Keep in mind that you cannot migrate their passwords.
Graph API - https://docs.microsoft.com/en-us/azure/active-directory-b2c/active-directory-b2c-devquickstarts-graph-dotnet
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