Lazysizes.min.js implementation not working – Shopify

We’re attempting to implement (https://github.com/aFarkas/lazysizes/tree/master) on https://berkshireblanket.com.

But after following all directions, the implementation will not work. When I run a check using DevTools, it outputs as false:

typeof($("img").lazyload) === "function"

I’m at a loss, and I’m not sure if we’re missing something either within the script or within the HTML.

Here’s a look at our HTML to show how it’s currently being implemented:

<div class="product-main-images {% if section.settings.thumbnails == 'bottom' %}desktop-12{% else %}desktop-10{% endif %} tablet-6 mobile-3" tabindex="0">
    <div class="product-image-container" style="padding-bottom: {{ product_image_box_ratio_max }};" >
    {% for image in product.images %}
    {% assign image_box_ratio = image.height | append: ".0" | times: 1 | divided_by: image.width | times: 100 | append: "%" %}
    {% assign img_url = image | img_url: '1x1' | replace: '_1x1.', '_{width}x.' %}

    <div class="product-main-image {% if forloop.first %}selected{% endif %}" data-image-id="{{ image.id }}">
        <a class="product-fancybox" rel="product-images"  href="{{ image | img_url: '2400x' }}" tabindex="-1">
            <img id="{{ product.id }}" class="product__image lazyload"
            src="{{ image | product_img_url: '300x' }}"
            data-src="{{ img_url }}"
            data-sizes="auto"
            data-zoom-src="{{ image | img_url: '2400x' }}"
            alt="{{ image.alt | escape }}">
        </a>
        <noscript>
            <img id="{{ product.id }}" class="product-main-image lazyload" src="{{ featured_image | product_img_url: '800x' }}" alt='{{ image.alt | escape }}'/>
        </noscript>
    </div>
    {% endfor %}
    </div>
</div>

I’d appreciate any help!

Please let me know if I can clarify anything, or provide further examples of our current implementation.

Thanks!