OLD = Issue 133 as published (Gemini 3.8 Flash-Lite in AI Studio). NEW = Google Cloud Text-to-Speech, voice Charon, new clearer pacing.
NO gemini-2.5-flash-tts HTTP 403: { "error": { "code": 403, "message": "Permission 'aiplatform.endpoints.predict' denied on resource '//aiplatform.googleapis.com/projects/986354430610/locations/global/publishers/google/models/gemini-2.5-flash-tts' (or it may not exist). Remediate access with this Troubleshooter URL or share it with your administrator - https://console.cloud.google.com/iam-admin/troubleshooter/summary;err
NO gemini-3.1-flash-tts-preview HTTP 403: { "error": { "code": 403, "message": "Permission 'aiplatform.endpoints.predict' denied on resource '//aiplatform.googleapis.com/projects/986354430610/locations/global/publishers/google/models/gemini-3.1-flash-tts-preview' (or it may not exist). Remediate access with this Troubleshooter URL or share it with your administrator - https://console.cloud.google.com/iam-admin/troubleshooter/sum