`stable-diffusion-x4-latent-upscaler` ID error

[ryan-seungyong-lee]

stability_api = client.StabilityInference(
    key=os.environ["STABILITY_KEY"],
    upscale_engine="stable-diffusion-x4-latent-upscaler",  # esrgan-v1-x2plus
    verbose=True,
)

esrgan-v1-x2plus works but stable-diffusion-x4-latent-upscaler makes error like below

debug_error_string = "UNKNOWN:Error received from peer ipv4:172.64.153.32:443 {created_time:"2023-11-21T01:36:01.677099235+09:00", grpc_status:5, grpc_message:"The specified engine (ID stable-diffusion-x4-latent-upscaler) was not found."}"