If you do not include taxes in your product prices, then taxes will not show up by default with cross sell (see this article for reference https://community.shopify.com/c/Shopify-Design/Product-pages-Show-VAT-prices-on-your-product-pages/m-p/614976 )

To get this done, you need to add a tax multiplier in our app's Settings -> Theme Then scroll down to Advanced section.

Example: If you use a 10% sales tax, then just add 10 to our app's tax multiplier and click save.

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