如何在木偶人Node.js中将常量添加到等待页.$x？xpath中的常量

const puppeteer = require('puppeteer');
require('dotenv').config();

(async () => {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  // 等待页的URL
  const url = 'https://example.com/waiting-page';
  await page.goto(url);
  
  // 在这里添加常量到等待页的XPath中
  const constant = 'your_constant_value';
  const xpath = `//*[text()="${constant}"]`;
  
  // 等待XPath元素出现
  await page.waitForXPath(xpath);
  
  // 其他操作...
  
  await browser.close();
})();