Sending data from virtual pin to populate a Database

Hello,
I’am working on a project with an ESP8266 and a Nova PM SDS011 sensor. All the data that I collect goes to an API through a local Blynk server.


void sendData(double z, double k, int a, int b, int c)
{

  StaticJsonBuffer<200> jsonBuffer;
  JsonObject &root = jsonBuffer.createObject();
  String string_a = String(a, 2);
  String string_b = String(b, 2);
  String string_c = String(c, 2);
  String string_z = String(z, 2);
  String string_k = String(k, 2);
  root["device"] = device_name;
  root["PM2_5"] = string_z;
  root["PM10"] = string_k;
  root["mixed_feeling"] = string_b;
  root["negative_feeling"] = string_c;
  root["positive_feeling"] = string_a;
  root["longitude"] = string_lat;
  root["latitude"] = string_lng;

  root.printTo(Serial);
  char JSONmessageBuffer[300];
  root.prettyPrintTo(JSONmessageBuffer, sizeof(JSONmessageBuffer));
  Serial.println(JSONmessageBuffer);

  if (WiFi.status() == WL_CONNECTED)
  { //Check WiFi connection status

    HTTPClient http;                                                    //Declare object of class HTTPClient
    http.begin("APIURL"); //Specify request destination
    http.addHeader("Content-Type", "application/json");                 //Specify content-type header
    int httpCode = http.POST(JSONmessageBuffer);                        //Send the request
    String payload = http.getString();                                  //Get the response payload
    Serial.println(httpCode);                                           //Print HTTP return code
    Serial.println(payload);                                            //Print request response payload
    http.end();                                                         //Close connection
  }
  else
  {
    delay(500);
    strip.setPixelColor(0, strip.Color(255, 200, 0)); //Orange
    strip.show();
    delay(500);
    strip.setPixelColor(0, strip.Color(30, 144, 255)); //Blue
    strip.show();
  }
}

All the data are sent by either the Nova PM or the GPS stream widget.
What I would like to do is to add in my iOS app, 3 buttons to populate the positive feeling, mixed feeling and negative feeling of my database which can be populate with a number. For now it is always on 0 but would like to add a 1 if I press on the push button of my app.

Do you know if there is a way to do that, I guess so but cannot find…

Thank you