MiniMax Speech 2.8 (GMI Cloud)

curl https://api.gmi-serving.com/v1/audio/speech \
  -H "Authorization: Bearer $GMI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "speech-2.8",
    "input": "欢迎使用 GMI Cloud 与 MiniMax 联合推出的高保真语音合成服务！"
  }'