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How to troubleshoot Product add-ons (List)?

Last updated on December 4, 2025

If your widget isn’t appearing on the product page, it could be due to several reasons. Please check the following:

  1. Confirm that the offer products are active and currently in stock.

  2. Make sure the BoostUp app embed is turned on in your theme. You can enable this through your theme customizer in the theme editor.

3. The “Add-ons List” app block is added in your theme. (2.0 theme).

4. For older themes that don’t support app blocks, you’ll need to manually adjust the placement.

5. If you continue to experience problems, reach out to our support team for complimentary setup help via chat, or book a Zoom session.

Problem: Add-ons not getting added to the cart

Solution:

At times, the app may fail to recognize the “Add to Cart” button on your store. This can happen due to a conflict with your theme or another third-party app.

To fix this, you can manually define the HTML/CSS selector of your “Add to Cart” button in the app’s admin settings.

Since identifying the correct selector can be a bit technical, our support team is always happy to help — feel free to reach out for free setup assistance.

However, if you’d like to handle it yourself, you can follow the step-by-step instructions below. You can also watch the tutorial video for a visual guide.

  1. Right-click on your product page.
  1. Click on “Inspect”.
  1. Once the screen opens, click on the small inspector tool icon, then click on the “Add to Cart” button.

  2. After this, a section will be highlighted in the console section.

  3. If the name="add" is not present, copy the class name from the highlighted section.
  1. Navigate to “Settings” from the BoostUp Upsell admin.
  1. Click on “Edit Settings” under Common Settings and Customizations.
  1. Paste the class name into the Add to cart button selector box under the Other Settings section.
  1. Save your changes and refresh your store.
  1. The add-ons should now be added to the cart.
  1. If you still face issues, contact our support team for free setup assistance.

Problem : I want to customize the widget appearance and styling

To update the look of your widget, follow these steps:

  1. Navigate to the “Customize” section in the app.

  2. Find the “Product Add-ons (List)” widget and click on “Edit widget”.

  3. Expand the various settings within the accordions to access more customization options and tweak the widget to your liking.

6. Save and exit.

7. Navigate to your store to see the changes made.

8. If you do not have the required supporting field here, custom CSS can be added.

Custom Css

If the required field isn’t available by default, you can still make the changes using custom CSS. To do this, go to the Customizer and at the top, select Common Settings and Customizations, then click on Edit Settings.

Add to cart button CSS selector

  • Identifies the button on your store that adds a product to the cart.

  • Helps the app detect when customers click the Add to Cart button.

  • Required for triggering upsells, bundles, or tracking add-to-cart actions.

Checkout button CSS selector

  • Identifies the checkout button in the cart or drawer.

  • Allows the app to perform actions when a customer proceeds to checkout.

  • Useful for showing last-minute upsells or tracking checkout conversions.

Variant separator

  • Defines the symbol used to separate variant options like color and size.

  • Example: in "Blue / XL", the separator is "/".

  • Helps the app correctly read and display variant details.

Custom CSS

  • Lets you apply custom styling to match the app’s appearance with your store’s theme.

  • Only for users familiar with CSS.

  • You can adjust button colors, borders, fonts, and layouts without editing theme files.

If you find this challenging, you can contact our customer support via chat or zoom for free setup assistance.