How to use the pyfcm.FCMNotification function in pyfcm

def __init__(self, conf, router_conf, metrics):
        """Create a new FCM router and connect to FCM"""
        self.conf = conf
        self.router_conf = router_conf
        self.metrics = metrics
        self.min_ttl = router_conf.get("ttl", 60)
        self.dryRun = router_conf.get("dryrun", False)
        self.collapseKey = router_conf.get("collapseKey", "webpush")
        self.senderID = router_conf.get("senderID")
        self.auth = router_conf.get("auth")
        self._base_tags = ["platform:fcm"]
        try:
            self.fcm = pyfcm.FCMNotification(api_key=self.auth)
        except Exception as e:
            self.log.error("Could not instantiate FCM {ex}",
                           ex=e)
            raise IOError("FCM Bridge not initiated in main")
        self.log.debug("Starting FCM router...")

"databaseURL": databaseURL,
  "storageBucket": ""
}

firebase = pyrebase.initialize_app(config_pyrebase)

mAuth = firebase.auth()
user = mAuth.sign_in_with_email_and_password(mail, password)
userID = mAuth.get_account_info(user['idToken'])
userID = userID["users"][0]["localId"]

db = firebase.database()
db_user = db.child("users").child(userID).get(user['idToken'])
deviceID = db_user.val()

push_service = FCMNotification(api_key=apiKeyFCM)

conn = sqlite3.connect('/opt/kripton-guard/network.db')

def createTables(conn):
    #Create db table if it's not exist
    conn.execute("CREATE TABLE mac_ip_addresses (ID INTEGER PRIMARY KEY AUTOINCREMENT, macAddress varchar(17) UNIQUE NOT NULL, ipAddress varchar(15) NOT NULL, comment varchar(50) )")

def showDevices():
    #Shows devices in whitelist
    print "\n========== Your Whitelist ==========\n    Mac Address       IP Address   "
    query = "SELECT macAddress,ipAddress FROM mac_ip_addresses;"
    result = conn.execute(query)
    for row in result:
        print row[0] + "    " + row[1] + "\n"
    print "==================================="

from pyfcm import FCMNotification
# fcm 푸쉬 메시지는 data message를 전송할 수 있다

fcm = FCMNotification(api_key='')

data = {'key1': 123, 'key2': 1234}
fcm.notify_single_device(data_message=data)

click_action=None,
        badge=None,
        color=None,
        tag=None,
        body_loc_key=None,
        body_loc_args=None,
        title_loc_key=None,
        title_loc_args=None,
        content_available=None,
        timeout=5,
        extra_notification_kwargs=None,
        extra_kwargs={}):

    if api_key is None:
        api_key = SETTINGS.get("FCM_SERVER_KEY")
    push_service = FCMNotification(api_key=api_key, json_encoder=json_encoder)
    result = push_service.notify_topic_subscribers(
        topic_name=topic_name,
        message_body=message_body,
        message_title=message_title,
        message_icon=message_icon,
        sound=sound,
        condition=condition,
        collapse_key=collapse_key,
        delay_while_idle=delay_while_idle,
        time_to_live=time_to_live,
        restricted_package_name=restricted_package_name,
        low_priority=low_priority,
        dry_run=dry_run,
        data_message=data_message,
        click_action=click_action,
        badge=badge,

def _get_push_service():
    return FCMNotification(api_key=_get_fcm_key())

import logging

from django.conf import settings
from pyfcm import FCMNotification

from foodsaving.subscriptions.models import PushSubscription

logger = logging.getLogger(__name__)

fcm = None

if hasattr(settings, 'FCM_SERVER_KEY'):
    fcm = FCMNotification(api_key=settings.FCM_SERVER_KEY)
else:
    logger.warning('Please configure FCM_SERVER_KEY in your settings to use push messaging')


def notify_multiple_devices(**kwargs):
    """
    Send a message to multiple devices.

    A simple wrapper of pyfcm's notify_multiple_devices.
    See https://github.com/olucurious/PyFCM/blob/master/pyfcm/fcm.py for more details on options, etc.
    """

    if fcm is None:
        return None

    response = fcm.notify_multiple_devices(**kwargs)

def __init__(self, config):
        self.config = config
        self.api_key = self.config.get('api_key')
        # FCM guarantees best-effort delivery with TTL 0
        self.ttl = self.config.get('ttl', 0)
        self.timeout = self.config.get('timeout', 10)
        self.default_notification = self.config.get('notification_title')
        self.proxy = None
        if 'proxy' in self.config:
            host = self.config['proxy']['host']
            port = self.config['proxy']['port']
            self.proxy = {'http': 'http://%s:%s' % (host, port),
                          'https': 'https://%s:%s' % (host, port)}
        self.client = FCMNotification(api_key=self.api_key, proxy_dict=self.proxy)

def send_push_notif(title, body):
    # Generate push service object
    push_service = FCMNotification(api_key=Constants.PUSH_ADDR)

    # Send push notif. to android and the notify_single_device returns result.
    ret = push_service.notify_single_device(registration_id=Constants.REG_ID, message_title=title, message_body=body)

    print(ret)

timeout (int, optional): set time limit for the request
    Returns:
        :dict:`multicast_id(long), success(int), failure(int),
            canonical_ids(int), results(list)`:
        Response from FCM server.

    Raises:
        AuthenticationError: If :attr:`api_key` is not set or provided or there
            is an error authenticating the sender.
        FCMServerError: Internal server error or timeout error on Firebase cloud
            messaging server
        InvalidDataError: Invalid data provided
        InternalPackageError: Mostly from changes in the response of FCM,
            contact the project owner to resolve the issue
    """
    push_service = FCMNotification(
        api_key=SETTINGS.get("FCM_SERVER_KEY") if api_key is None else api_key,
        json_encoder=json_encoder,
    )
    return push_service.single_device_data_message(
        registration_id=registration_id,
        condition=condition,
        collapse_key=collapse_key,
        delay_while_idle=delay_while_idle,
        time_to_live=time_to_live,
        restricted_package_name=restricted_package_name,
        low_priority=low_priority,
        dry_run=dry_run,
        data_message=data_message,
        content_available=content_available,
        timeout=timeout,
        extra_notification_kwargs=extra_notification_kwargs,