You can also use Puppeteer to find elements with XPath instead of CSS selectors, by using the page.$x() function:
const puppeteer = require('puppeteer');
(async () => {
const browser = await puppeteer.launch();
const page = await browser.newPage();
// Open Scrapingbee's website
await page.goto('https://scrapingbee.com');
// Get the first h1 element using page.$x
let first_h1_element = await page.$x('//*[@id="content"]/div/section[1]/div/div/div[1]/div/h1');
// Get all p elements using page.$x
let all_p_elements = await page.$x("//p");
// Get the textContent of the h1 element
let h1_value = await page.evaluate(el => el.textContent, first_h1_element[0])
// The total number of p elements on the page
let p_total = await page.evaluate(el => el.length, all_p_elements)
console.log(h1_value);
console.log(p_total);
// Close browser.
await browser.close();
})();