Error "jQuery is not defined" after "quickstart" using "influencer" them

I am trying to setup a website with “influencer” theme. I followed “quickstart” steps.
This is what I get in my terminal when I enter hugo server -D:
And this is what I see in my web browser on localhost:1313:

I searched on the internet for “jQuery is not defined.” I found this blog post suggesting that:

  • “CDN-hosted jQuery might be blocked”
  • “Your CDN-hosted jQuery is down or timing out”

The blog post suggests this solution below but I don’t know if that is relevant to hugo.

// First try loading jQuery from Google's CDN
<script src="//"></script>

// Fall back to a local copy of jQuery if the CDN fails
window.jQuery || document.write('<script src=""><\/script>'))

Let me know if you have a suggestion on how I can make my hugo website render like the “influencer” theme.