@Jolienai Ribeiro Viegas
Thank you for your detailed post and I apologize for the delayed response!
Based off your error message and our supported B2C Graph API operations article, the "passwordAuthenticationMethod: resetPassword" API is not supported for B2C. As of right now, only the GET/Update APIs are supported via the - User flow authentication methods (beta).
Error Message:
Microsoft.Graph.ServiceException: Code: methodNotAllowed
Message: The method is not supported for this URL.
If you'd like, I'd recommend leveraging our User Voice forum to create a feature request so our engineering team can take a look at implementing this.
If you have any other questions, please let me know.
Thank you for your time and patience throughout this issue.
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