如何确定按下了哪个按钮

<button id="button1" onclick="handleButtonClick(event)">按钮1</button>
<button id="button2" onclick="handleButtonClick(event)">按钮2</button>

<script>
function handleButtonClick(event) {
  var clickedButtonId = event.target.id;
  console.log("按下了按钮：" + clickedButtonId);
}
</script>

// 前端发送请求的代码
fetch('/buttonClick', {
  method: 'POST',
  body: JSON.stringify({ buttonId: 'button1' }),
  headers: { 'Content-Type': 'application/json' }
});

// 后端处理请求的代码
app.post('/buttonClick', (req, res) => {
  var clickedButtonId = req.body.buttonId;
  console.log("按下了按钮：" + clickedButtonId);
  // 进行相应的处理
});

const { app, BrowserWindow } = require('electron');

function createWindow() {
  const mainWindow = new BrowserWindow();
  mainWindow.loadFile('index.html');

  mainWindow.webContents.on('did-finish-load', () => {
    const button1 = mainWindow.webContents.getElementById('button1');
    const button2 = mainWindow.webContents.getElementById('button2');

    button1.addEventListener('click', () => {
      console.log("按下了按钮：button1");
    });

    button2.addEventListener('click', () => {
      console.log("按下了按钮：button2");
    });
  });
}

app.whenReady().then(createWindow);