For the new Shopify's 2.0 theme, we don't have the product.liquid and cart.liquid files. When you want to add Cross Sell to the 2.0 theme, you will need to customize your product and cart pages and add the Cross Sell blocks as shown below:

Check out the video here:

Follow the steps below:

1. After you click on customize your theme, click on the Home Page dropdown and select the Products option as shown below

2. Select the Default product option

3. On the left sidebar, click on Add section to view the cross sell widgets

4. Select General to add cross sells to your page then click on Add selection again to add Quickview & Upsell if you want the Pop-up to display on your product page and click on save.

5. For adding Cross Sells on the Cart page, Click again on the dropdown at the top of the page and select Cart.

6. Click on Add section to add the General cross sell widget.

7. Select the General widget and click on save at the top right corner.

You are Done!

Remember to always click on save after any changes you make.

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