Get URL in group pictures - Instagram Scrap with Puppeteer.js

const browser = await puppeteer.launch();

const page = await browser.newPage();
await page.goto('https://www.instagram.com/p/B3UZAnJHCOX/');

await page.content()
const len = await page.evaluate(() => {
  len = (document.querySelector('._6CZji .coreSpriteRightChevron')) ? document.querySelectorAll('div.tN4sQ li._-1_m6').length : 1
  return Promise.resolve(len);
});
console.log(len);
for (i = 0; i < len; i++) {
  let url = await page.evaluate(x => {
    imgs = document.querySelectorAll('._97aPb img');

    btn = document.querySelector('._6CZji .coreSpriteRightChevron')
    if (btn) btn.click()
    
    if (x == 0) {
      if (imgs[0].className == "_8jZFn") return Promise.resolve(imgs[0].previousSibling.getAttribute('src')); // it's a video
      return Promise.resolve(imgs[0].getAttribute('src'));
    }
    
    if (imgs[1].className == "_8jZFn") return Promise.resolve(imgs[1].previousSibling.getAttribute('src'));
    return Promise.resolve(imgs[1].getAttribute('src'));
  }, i);

  console.log(url);
  await page.waitFor(450);  //TODO: Wait for transition to end. Hardcoded.
}
await page.screenshot({
  path: 'screenshot.png'
});
await browser.close();