Hello @Vedran Opančar - dotSource SE,
Thank you for posting your query on Microsoft Q&A.
As @Abiola Akinbade mentioned, the difference between your test tenant and the client’s tenant is due to the roles assigned to your user account. In your test tenant, you can perform actions in the External ID tenant because you have the Global Administrator role. However, in the client’s tenant, where you only have the "Application Administrator" and "Cloud Application Administrator" roles, you lack the necessary permissions to manage or make changes to Entra features.
To manage conditional access policies, you need to have at least the Conditional Access Administrator or Security Administrator role assigned.
To manage user flows, your account must have the External ID User Flow Administrator role.
Additionally, if you are encountering any error messages when trying to create a Custom Authentication Extension (Preview), please share a screenshot of the error. This will help us troubleshoot the issue more effectively.
You also mentioned that some features currently in Preview are unavailable for use. Could you provide more details about these options so we can investigate and provide further guidance?
I hope this information is helpful. Please feel free to reach out if you have any further questions.
Thanks,
Raja Pothuraju.