Please Help me this function doesn't fire from the periperical?

Official Hardware Nano Family Nano 33 IoT
5 
#include <ArduinoBLE.h>

BLEService ledService("77B10000-E8F2-537F-4F6C-D104768A1777"); // BLE LED Service

// BLE LED Switch Characteristic - custom 128-bit UUID, read and writable by central
BLEByteCharacteristic switchCharacteristic("77B10001-E8F2-537F-4F6C-D104768A1777", BLERead | BLEWrite);

const int ledPin = LED_BUILTIN; // pin to use for the LED

void setupToConfigLedAndBle() {
  
  Serial.begin(9600);
  while (!Serial);

  // set LED pin to output mode
  pinMode(ledPin, OUTPUT);

  // begin initialization
  if (!BLE.begin()) {
    Serial.println("starting BLE failed!");

    while (1);
  }

  BLE.setLocalName("xxxxxx");
  BLE.setDeviceName("xxxxxx");

  String address    = BLE.address();


  BLE.setAdvertisedService(ledService);

  // add the characteristic to the service
  ledService.addCharacteristic(switchCharacteristic);

  // add service
  BLE.addService(ledService);

  // set the initial value for the characeristic:
  switchCharacteristic.writeValue(0);

  // start advertising
  BLE.advertise();

  Serial.println("xxxxxx visible...");

}