Hi @walter.adbe,
Thanks for reaching out to the Auth0 Community!
After looking carefully at the code snippet you shared, I noticed that the audience parameter you passed is not an audience defined in your API settings.
Could you please ensure the audience parameter points to an audience identifier of one of your APIs?
And could you please make sure you are also passing the client_secret parameter in the request? This is needed for confidential clients.
Please let me know how this goes for you.
Thanks,
Rueben