def should_use_granian():
    """Whether to use Granian for backend.

    Returns:
        True if Granian should be used.
    """
    if environment.REFLEX_USE_GRANIAN.is_set():
        return environment.REFLEX_USE_GRANIAN.get()
    if (
        importlib.util.find_spec("uvicorn") is None
        or importlib.util.find_spec("gunicorn") is None
    ):
        return True
    _warn_user_about_uvicorn()
    return False
Whether to use Granian for backend.

    Returns:
        True if Granian should be used.
    
reflex/utils/exec.py