Lightbox / load more does not work, console reports TypeError

I'm trying to get the portfolio working on my site . It's a very simple site, no other extensions or modifications except JUX Portfolio and a theme.

Nothing happens when I click a photo: I get the hover effect, but no lightbox appears.

In the chrome console, I get the following when the page is loaded:
Uncaught TypeError: jQuery(...).nivoLightbox is not a function

It seems to be relating to this section of the code:
<script type="text/javascript">
jQuery(document).ready(function(){
jQuery('.jux-lightbox').nivoLightbox();
});
</script>

Hi Sofie.
Thank you for using our product,
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I will check it for you soon,