source tts-hs-hifigan/bin/activate
CUDA_VISIBLE_DEVICES="" gunicorn -w 2 -b 0.0.0.0:5000 flask_app:app --timeout 600 --daemon #--certfile ./certificate.pem --keyfile ./key.pem
# set CUDA_VISIBLE_DEVICES= "" for cpu, 0 for GPU-0, 1 for GPU-1 ...