Thank you for posting this in Microsoft Q&A.
I understand you are encountering an authentication issue with React when using the application type as multi-tenant in external tenants.
AADSTS500207: The account type can't be used for the resource you're trying to access. when i changing application type to single tenant or trying with empty scope it is working fine what was the issue?
As of today, accessing API of workforce tenant from external tenant (CIAM User) is not supported.
Meanwhile, we suggested a workaround for this issue: use an external ID for Workforce tenants, which allows for B2B collaboration. This would be the same as the External ID in External tenants (CIAM), but the users will be hosted in the same production tenant as guest users.
However considering the feature to be new, we are open for feedback and request you to post this as an idea on our feedback forum so that it could be visible to the service engineering team.
Similar issue discussed earlier in Microsoft Q&A platform: https://learn.microsoft.com/en-us/answers/questions/1665201/how-to-give-external-customer-accounts-in-a-entra
User shared an idea on our feedback forum https://feedback.azure.com/d365community/idea/a02a5bb4-4b13-ef11-9899-6045bd824b24 Appreciate if you could upvote and comment on. This allows our product teams to effectively prioritize your request against our existing feature backlog and gives insight into the potential impact of implementing the suggested feature.
Hope this helps. Do let us know if you any further queries.
Thanks,
Navya.
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