Hmac sha256 url parameter signature validate using dart and nodejs

app.js

// Dart
void _incrementCounter() {
    String secret = "762c4144-1630-4fab-9161-0fef8b18d316";
    List<int> key = utf8.encode(secret);

    String message = "clientId=android-app&type=action&ts=1550493108338&actions=%5B%7B%22name%22%3A%22setOn%22%2C%22parameters%22%3A%7B%7D%7D%5D";
    List<int> messageBytes = utf8.encode(message);
    
    Hmac hmac = new Hmac(sha256, key);
    Digest digest = hmac.convert(messageBytes);
    String base64Mac = base64.encode(digest.bytes);
    print("base64Mac: " + base64Mac);
  }
  
// Nodejs
  
let query = "clientId=android-app&type=action&ts=1550493108338&actions=%5B%7B%22name%22%3A%22setOn%22%2C%22parameters%22%3A%7B%7D%7D%5D";
const crypto = require("crypto");
const key = Buffer.from("762c4144-1630-4fab-9161-0fef8b18d316", 'utf8');
console.log("key:" + key.toString('utf8'));
let computedSignature = crypto.createHmac("sha256", key).update(query, 'utf8').digest('base64');
console.log(computedSignature);