#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
const char* ssid = "Dinos LAN#3";
const char* password = "15gbfggf4eztmm456zb4";
String test = "";
ESP8266WebServer server(80);
void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
  {
    Serial.println("wifi");
    delay(500);
  }
  server.begin();
  if (MDNS.begin("aqa")) {
    Serial.println("dns");
  }
  server.on("/toggle", HTTP_GET, toggle);
}

void loop() {
  delay(2500);
  server.handleClient();
  Serial.println("loop " + test);
}

void toggle() {
  Serial.println(test);
  if(test == "on") {
    String test = "off";
    server.send(200, "text/html", "off");
    Serial.println(test);
  } else {
    String test = "on";
    server.send(200, "text/html", "on");
    Serial.println(test);
  }
}


Ausgabe vom Seriellen Monitor wenn ich die Webseite dann aufrufe
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wifi
wifi
wifi
dns
loop
loop
loop
loop

on
loop

on
loop

on
loop
loop
loop