Fire-Base-Send-Notifications.txt

public string SEND_PUSH_NOTIFICATION()
{
    // one or more ids. Change "ANDROID_CLIENT_ID" with real ids
    var REGISTRATIONS_IDS = new List<string>() { "ANDROID_CLIENT_ID" };
    
    Dictionary<string, string> OptionalData = new Dictionary<string, string>()
    {
        { "Category", "NEW_INDIVIDUAL_REQUEST"},
        { "Title", "Title"},
        { "SubTitle", "SubTitle"}
    };

    var data = new
    {
        registration_ids = REGISTRATIONS_IDS,
        data = new { OptionalData }
    };
    
    // json encode data
    var json = new JavaScriptSerializer().Serialize(data);
    Byte[] byteArray = Encoding.UTF8.GetBytes(json);

    var FCM_ServerID = "FCM_ServerID"; //"AAAAFcVaokE:APA91bGvdGCfclPKUhyLCesDygpOPPPQ5tv1j00hlR3rnqk6bv7D7fVkplTSrlUYqj"
    var FCM_SENDER_ID = "FCM_SENDER_ID"; // "935053234525"


    WebRequest webRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");
    webRequest.Method = "post";
    webRequest.ContentType = "application/json";
    webRequest.Headers.Add($"Authorization: key={FCM_ServerID}");
    webRequest.Headers.Add($"Sender: id={FCM_SENDER_ID}");
    webRequest.ContentLength = byteArray.Length;
    Stream stream = webRequest.GetRequestStream();
    stream.Write(byteArray, 0, byteArray.Length);
    stream.Close();

    WebResponse webResponse = webRequest.GetResponse();
    stream = webResponse.GetResponseStream();
    StreamReader streamReader = new StreamReader(stream);
    var finalResponse = streamReader.ReadToEnd();
    
    streamReader.Close();
    stream.Close();
    webResponse.Close();
    
    return Content(finalResponse);
}

This is a way to big code for a curl request. Use any c# curl library instead.