code highlight in the lecture page

Hi, I want to apply prism.css, prism.js in the code chunk in the lecture page but I can't apply the custom class in the code block in the lecture page. Any body has an idea?

for example, the below code block

import numpy as np

i want to make

<pre>
  <code class="language-python">
    import numpy as np
  </code>
</pre>

However, In the course page, when i tried to put code block, it looks like this:

<pre class="wp-block-code">
    <code>
      import numpy as np
    </code>
</pre>