title: NextJS CSP header destroying PDFtron iframe content
body: <p>I recently added CSP header to my project.
  At the same time, I am also using PDFTron webviewer in my project.
  As you know, PDFTron webviewer is rendered in an iframe and after adding CSP headers, I'm getting below error - related frame-ancestors.</p>
  <p><a href="https://i.stack.imgur.com/W8o2b.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/W8o2b.png" alt="enter image description here" /></a></p>
  <p><strong>Question1</strong> is how can I add a frame-ancestors header to the PDFtron webviewer to bypass this error?</p>
  <p><strong>Question2</strong> is the second error related with cross domain is not fixable by adding my domains to <code>configorigin.txt</code>, is it related with the csp header setting?</p>