I’ve got this code:

#include <WiFi.h>
#include <DNSServer.h>
#include "gateway.h"
#include <HTTPClient.h>

// Variables for Server
const byte DNS_PORT = 53;
IPAddress apIP(8, 8, 4, 4); // The default android DNS
DNSServer dnsServer;
WiFiServer server(80);

int counter=0;

String currentIP = "192.168.0.100";

String responseHTML = getHTML();

const char *serialNum;
const char *ipAddr;

String sNumForHTML = "";
String ipForHTML = "";
int incomingByte = 0;


// Function for starting server
void setup() {
  Serial.begin(115200);
  Serial.println("Starting AP and connecting to WiFi network");

  // Start AP mode
  WiFi.mode(WIFI_AP_STA);
  WiFi.softAP("Gateway_server");
  WiFi.softAPConfig(apIP, apIP, IPAddress(255, 255, 255, 0));

  // Start DNS Server
  dnsServer.start(DNS_PORT, "*", apIP);
  

  // Start web server
  server.begin();
}

// Function which get cast one time of each frame
void loop() {
  if (Serial.available() > 0) {
    // read the incoming byte:
    String value = Serial.readString();
    Serial.print("incoming Value: ");
    Serial.println(value); 
  }
  dnsServer.processNextRequest();
  WiFiClient client = server.available(); // listen for incoming clients
  if (client) {
  // send data only when you receive data:
    String currentLine = "";
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        if (c == 'n') {
          if (currentLine.length() == 0) {
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println();
            client.print(responseHTML);
            break;
          } else {
            currentLine = "";
          }
        } else if (c != 'r') {
          currentLine += c;
        }
      }
    }
    client.stop();
  }
}

It creates a Captive Portal-Server on my ESP32 how can i send Data (like a IP-String) which i insert in a textfield on the captive portal webview (Response HTML) to this arduino code to manage it?

I know how i can get the input of a text field in HTML using JS but how can i send it to the ardunio code which upload the webview?

Or is it even possible?

THX for helping.

I tried to solve this problem using serial or http requests but it didn’t work.