ESP8266 NODEMCU V3 web server with MAX7219 and DS3231 RTC

Question

I am using ESP8266 NodeMCU with MAX7219 and a DS3231 teal time clock. I want to display the time and some text. The display is made of 4 FC16 modules which are made of 4 8x8 MAX7219 led matrix modules so it would be a 32x32 led matrix diplay divided in 4 rows. I am displaying the time hh:mm on the last row and text on the first 3 rows.

With ESP8266 I connected to my wi-fi and I created a web server which says "Hello World!"

So my question is: how do I upload my code to the web server so I can change the text remotely?

I found this tutorial https://maker.pro/esp8266/tutorial/how-to-build-an-led-matrix-display-with-a-nodemcu-esp8266 that shows how to change the text on one row of display but I don't want something that fancy. I just want my code uploaded and to be able to change in the code.

#include "RTClib.h"
#include <MD_Parola.h>
#include <MD_MAX72xx.h>
#include <SPI.h>
#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
ESP8266WebServer server;
// Define the number of devices we have in the chain and the hardware interface
// NOTE: These pin numbers will probably not work with your hardware and may
// need to be adapted
#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define MAX_DEVICES 12
#define NUM_ZONES 3
int CS_PIN = D4;
int CLK_PIN = D5;
int DATA_PIN = D7;
// Hardware SPI connection
MD_Parola P = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);
// Arbitrary output pins
// MD_Parola P = MD_Parola(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);
RTC_DS3231 rtc;
#define SPEED_TIME  25
#define PAUSE_TIME  1000
uint8_t lastUpdateMin = 0;
uint8_t lastUpdateHour = 0;
// Global variable
const char  *pc[NUM_ZONES] =
{
  "TIME", //0
  "ROOM", //1
  "SUBJECT", //2
  //"GRADE",//3
};
void setup(void)
{
  Serial.begin(115200);
  Serial.println();
WiFi.begin("ssid", "password");
Serial.print("Connecting");
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println();
Serial.print("Connected, IP address: ");
  Serial.println(WiFi.localIP());
  server.on("/",  {
    server.send(200, "text/plain", "Hello World!");
  });
  server.begin();
P.begin();
  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }
if (rtc.lostPower()) {
    Serial.println("RTC lost power, lets set the time!");
    //     If the RTC have lost power it will set the RTC to the date & time this sketch was compiled in the following line
    rtc.adjust(DateTime(F(DATE), F(TIME)));
  }
P.begin(3);
  P.setZone(0, 0, 3); // Modules 0-3 in zone 0
  P.setZone(1, 4, 7); // Modules 4-7 in zone 1
  P.setZone(2, 8, 11); // Modules 8-11 in zone 2
  // P.setZone(3, 12, 15); // Modules 12-15 in zone 3
}
void loop(void)
{
  server.handleClient();
  DateTime now = rtc.now();
  if (lastUpdateMin != now.minute()) { // change every minute
    lastUpdateMin = now.minute();
    char buffer[] = "hh:mm";  // hours and minutes
    P.displayZoneText(0, now.toString(buffer), PA_CENTER, 0, 0, PA_PRINT, PA_NO_EFFECT);
  }
  if (lastUpdateHour != now.hour()) {   // change every hour
    lastUpdateHour = now.hour();
    P.displayZoneText(1, pc[1], PA_CENTER, 0, 0, PA_PRINT, PA_NO_EFFECT);  // 2nd row
    P.displayZoneText(2, pc[2], PA_CENTER, 0, 0, PA_PRINT, PA_NO_EFFECT);   // 3rd row
    //   P.displayZoneText(3, pc[3], PA_CENTER, 0, 0, PA_PRINT, PA_NO_EFFECT); // 4th row
  }
  P.displayAnimate();
}