Some people have also liked this question, so thought of providing the solution I implemented, thinking it may help others. Please feel free to ask questions, if you have any.
How to get the Server Key: Here is the question link which helps.
Firebase Cloud Messaging Documentation can be found here.
public class FirebaseNotificationModel
{
    [JsonProperty(PropertyName = "to")]
    public string To { get; set; }
    [JsonProperty(PropertyName = "notification")]
    public NotificationModel Notification { get; set; }
}
using System.Net.Http;
using System.Text;
public static async void Send(FirebaseNotificationModel firebaseModel)
{
    HttpRequestMessage httpRequest = null;
    HttpClient httpClient = null;
    var authorizationKey = string.Format("key={0}", "YourFirebaseServerKey");
    var jsonBody = SerializationHelper.SerializeObject(firebaseModel);
    try
    {
        httpRequest = new HttpRequestMessage(HttpMethod.Post, "https://fcm.googleapis.com/fcm/send");
        httpRequest.Headers.TryAddWithoutValidation("Authorization", authorizationKey);
        httpRequest.Content = new StringContent(jsonBody, Encoding.UTF8, "application/json");
        httpClient = new HttpClient();
        using (await httpClient.SendAsync(httpRequest))
        {
        }
    }
    catch
    {
        throw;
    }
    finally
    {
        httpRequest.Dispose();
        httpClient.Dispose();
    }
}