title: How switch to iFrame with Cypress
body: <p>I use Cypress to automate logging in to a web application, protected by an iFrame.</p>
  
  <p>In my Selenium I can use a command to switch to iFrame:</p>
  
  <pre><code>driver.switchTo().frame(driver.findElement(By.xpath(".//*@id='app']/iframe")));
  </code></pre>
  
  <p>After that I can access iFrame elements as well.</p>
  
  <p>But with Cypress, I don't know the method to switch to frame?</p>