Example puppeteer setup for Joe McCann

screenshot.js

const puppeteer = require('puppeteer');

const config = {
  entryUrl: '',
  auth: {
    email: '',
    emailSelector: '',
    password: '',
    passwordSelector: '',
    submitButtonSelector: '' 
  },
  dataSelector: '',
  inputSelector: '',
  input: '',
  inputSubmitSelector: '',
  modalTriggerSelector: '',
  targetSelector: '',
  screenShotPath: ''
};


(async () => {
  const browser = await puppeteer.launch({
    headless: false,        // remove this once this works
    defaultViewport: null,  // account for wonky viewport bug on mac
  });
  const [ page ] = await browser.pages();

  // Start page
  await page.goto(config.entryUrl);

  // Auth
  await page.type(config.emailSelector, config.email);
  await page.type(config.passwordSelector, config.password);
  await page.click(config.submitButtonSelector);
  
  // This may be better as a waitForResponse();
  // https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#pagewaitforresponseurlorpredicate-options
  await page.waitForNavigation();

  // Click on the Data element. You may be able to just navigate directly to the URL
  // if the app allows it
  await page.click(config.dataSelector);

  // same as above wrt:waitForResponse();
  await page.waitForNavigation();

  // Enter the "DAYS" input and click on the button
  await page.type(config.inputSelector, config.input);
  await page.click(config.dataSelector);

  // same wrt:waitForResponse();
  await page.waitForNavigation();

  // Click on selector for "Bitmex funding rate"
  await page.click(config.modalTriggerSelector);

  // This is probably better waiting for something specific about the modal/graphic
  // maybe an animation end or an event. 
  await page.waitFor(1000);

  // Grab the element that we want to screenshot
  const target = page.$(config.targetSelector);

  // You can omit the path and have this return a buffer
  await target.screenshot({path: config.screenShotPath});

  await browser.close();
})();

The awaits can be combined in whatever promise-managing way you want. I left them all flat because it'll be easier to test and cut/copy/paste during troubleshooting.