how to make Utteranc.es theme follow archie's?

[anthonyhan]

hello, I am a total beginer in web dev. I want to add comment system named "Utteranc.es" in archie. But I got some problems.

<script src="https://utteranc.es/client.js"
        repo="[ENTER REPO HERE]"
        issue-term="pathname"
        theme="github-dark"
        crossorigin="anonymous"
        async>
</script>

my plan is, the theme of utterances follows archie's dark/light mode.
I tried the way like theme="github-{{mode}}" but failed.
But I can not find a way to do it. Any suggestions would be very appreciated!