How to use the configargparse.init_argument_parser function in ConfigArgParse

def init_argparser():
    config_home = os.getenv('XDG_CONFIG_HOME', '~/.config')
    home = os.path.expanduser('~')
    if config_home.startswith(home):
        config_home = '~' + config_home[len(home):]
    config_file = os.path.join(config_home, 'blitzloop', 'blitzloop.conf')
    configargparse.init_argument_parser(
            default_config_files=['/etc/blitzloop/blitzloop.conf', config_file])
    parser = configargparse.get_argument_parser()
    parser.add_argument(
        '--fullscreen', default=False, action='store_true',
        help='run blitzloop fullscreen')
    parser.add_argument(
        '--display', default="glut",
        help='Choose a display backend')
    parser.add_argument(
        '--mpv-audio-device', default="jack",
        help='Audio output driver and device for libmpv')
    parser.add_argument(
        '--mpv-ao', default=None,
        help='Audio output driver for libmpv (deprecated, use --mpv-audio-device)')
    parser.add_argument(
        '--mpv-options', default="",