How to use the pywebpush.webpush function in pywebpush

vapid_data = {}

    webpush_settings = getattr(settings, 'WEBPUSH_SETTINGS', {})
    vapid_private_key = webpush_settings.get('VAPID_PRIVATE_KEY')
    vapid_admin_email = webpush_settings.get('VAPID_ADMIN_EMAIL')

    # Vapid keys are optional, and mandatory only for Chrome.
    # If Vapid key is provided, include vapid key and claims
    if vapid_private_key:
        vapid_data = {
            'vapid_private_key': vapid_private_key,
            'vapid_claims': {"sub": "mailto:{}".format(vapid_admin_email)}
        }

    try:
        req = webpush(subscription_info=subscription_data, data=payload, ttl=ttl, **vapid_data)
        return req
    except WebPushException as e:
        # If the subscription is expired, delete it.
        if e.response.status_code == 410:
            subscription.delete()
        else:
            # Its other type of exception!
            raise e

def notifyNewAgent():
    dashboard_notifications = db.session.query(DashboardRegistration).all()
    if dashboard_notifications is not None:
        for registration in dashboard_notifications:
            try:
               webpush(
                   subscription_info={
                    "endpoint": registration.endpoint,
                    "keys": {
                      "p256dh": registration.authKey,
                      "auth": registration.authSecret
                     }
                   },
                   data="",
                   vapid_private_key="./private_key.pem",
                   vapid_claims={
                    "sub": "mailto:YourNameHere@example.org",
                   }
               )
            except WebPushException as ex:
                print(ex)
                return

def _send_webpush(subscription_info: dict, data: dict) -> bool:
    """
    Send a webpush message asynchronously
    """
    if not WEB_PUSH_ENABLED:
        return False

    json_data = json.dumps(data)

    try:
        webpush(
            subscription_info=subscription_info,
            data=json_data,
            vapid_private_key=VAPID_PRIVATE_KEY,
            vapid_claims=VAPID_CLAIMS,
        )
        return True
    except WebPushException as error:
        logger.error(error)
        # Mozilla returns additional information in the body of the response.
        if error.response and error.response.json():
            logger.error(error.response.json())
        return False
    except TypeError as error:
        logger.error(error)
        raise error

async def send_web_push(subscription_information, message_body):
    claims = dict(settings.VAPID_CLAIMS)
    try:
        return webpush(
            subscription_info=subscription_information,
            data=message_body,
            vapid_private_key=settings.VAPID_PRIVATE_KEY,
            vapid_claims=claims,
        )
    except WebPushException as ex:
        logger.exception("Exception while trying to send push notification")

        if ex.response and ex.response.json():
            extra = ex.response.json()
            logger.info(
                "Remote service replied with a %s:%s, %s",
                extra.code,
                extra.errno,
                extra.message,
            )

def main():
    """ Send data """

    try:
        args = get_config()
        result = webpush(
            args.sub_info,
            data=args.data,
            vapid_private_key=args.key,
            vapid_claims=args.claims,
            curl=args.curl,
            content_encoding=args.encoding,
            verbose=args.verbose)
        print(result)
    except Exception as ex:
        print("ERROR: {}".format(ex))