Supply theme

1. In your Shopify Admin click Online Store.
2. Click to Current Theme's Actions > Edit code.
3. Open the product-template.liquid file under the Sections area of your Theme Editor.
4. Copy the code below.

   {% unless product.metafields.coattend.enabled %}
    <button type="submit" name="add" id="addToCart-{{ section.id }}" class="{{ btn_class }} btn--add-to-cart{% if section.settings.enable_payment_button %} btn--secondary-accent{% endif %}">
        <span class="icon icon-cart"></span>
        <span id="addToCartText-{{ section.id }}">{{ 'products.product.add_to_cart' | t }}</span>
    </button>
    {% if section.settings.enable_payment_button %}
        {{ form | payment_button }}
    {% endif %}
   {% else %}
    <div class="coattend-button {{ btn_class }} btn--add-to-cart{% if section.settings.enable_payment_button %} btn--secondary-accent{% endif %}"
            data-coattend-product-id="{{product.id}}" 
            data-coattend-variant-id="{{product.selected_variant.id}}">
        <span class="icon icon-cart"></span>
        <span id="addToCartText-{{ section.id }}">{{ 'products.product.add_to_cart' | t }}</span>
    </div>
   {% endunless %}

5. Replace code from line 192 to 199. You can see what needs to be replaced on the below image. Supply theme code that needs to be replaced.
6. Click Save

Congratulations! Continue and display your event.