Using Upsells' Cart with Replo Landing Page Designer.

1. Locate and click on the add-to-cart custom button -> click on the Settings button, and click the Interactions tab on the right-hand panel.

2. Make sure that the Add Product to Cart interaction of your add-to-cart button has both "Go to cart after?" and "Go to checkout after?" disabled, if they're not, disable them and click Save.

3. Click on the "+" in the On Click menu and add an interaction called “Run JavaScript” for each custom add-to-cart button. Here’s a reference GIF:

4. Once you’ve added the "Run JavaScript" interaction, insert the following code in the Launch code editor option and make sure to save it; if done correctly, the new Run Javascript interaction should display below the "Add Product to Cart" option.

window.AMP_API.OPEN_CART();

Then, publish your Replo Page, and that should do it!