This sample code is use to control the LED strip using Blynk App and ESP32.

stripESP32.ino

#define BLYNK_PRINT Serial
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
#include <Adafruit_NeoPixel.h>
#include <SPI.h>

#define PIN 27
#define NUMPIXELS 30
#define BLYNK_PRINT Serial
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "YourAuthToken";

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "YourNetworkName";
char pass[] = "YourPassword";

BLYNK_WRITE(V2)
{
  int R = param[0].asInt();
  int G = param[1].asInt();
  int B = param[2].asInt();
  Serial.println(R);
  Serial.println(G);
  Serial.println(B);
  for (int i = 0; i < NUMPIXELS; i++) {

    pixels.setPixelColor(i, pixels.Color(R, G, B));

    pixels.show();
  }
}

void setup()
{
  // Debug console
  Serial.begin(9600);
  Blynk.begin(auth, ssid, pass);
  pixels.begin();
}

void loop()
{
  Blynk.run();
}