Azure Function implementation that listens to Cosmos DB updates and sends notification to Android

NotifyOnPromo.cs

using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.Azure.Documents;
using Microsoft.Azure.NotificationHubs;
using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;

namespace PromoNotificationFunc
{
    public static class NotifyOnPromo
    {
        [FunctionName(nameof(NotifyOnPromo))]
        public static async Task Run([CosmosDBTrigger(
            databaseName: "iqanscosmosdb1",
            collectionName: "promo",
            ConnectionStringSetting = "CosmosDB.ConnectionString",
            LeaseCollectionName = "leases")]IReadOnlyList<Document> input, ILogger log)
        {
            if (input != null && input.Count > 0)
            {
                log.LogInformation("Documents modified " + input.Count);
                var promoText = input[0].GetPropertyValue<string>("text");
                log.LogInformation("Promo Id " + input[0].Id);
                log.LogInformation("Promo Text " + promoText);

                var connectionString = "REPLACE WITH YOUR NOTIFICATION HUB CONNECTION STRING";
                var hubName = "REPLACE WITH YOUR NOTIFICATION HUB NAME";
                var nhClient = NotificationHubClient.CreateClientFromConnectionString(connectionString, hubName);

                var notificationPayload = "{\"data\":{\"body\":\"" + promoText + "\",\"title\":\"" + input[0].Id + "\"}}";
                var notification = new FcmNotification(notificationPayload);

                var outcomeFcmByTag = await nhClient.SendFcmNativeNotificationAsync(notificationPayload);
            }
        }
    }
}