I want to use highlight.js in my website.But it doesn't work.
I use unpkg CDN and I import it like that:

<link rel="stylesheet" href="https://unpkg.com/@highlightjs/cdn-assets@11.5.0/styles/rainbow.min.css">
<script src="//unpkg.com/@highlightjs/cdn-assets@11.5.1/highlight.min.js"></script>

and I also use <script>hljs.highlightAll();</script> in the end of my file.
I couldn't find anything wrong, but it still report a warning like that: screenshot

Can any one help me? Thanks!