Add an “upsell” add to cart button in checkout

[Maritimefamily]

I sell yarn, but I recently listed my daughter’s felted animals to my shop for $4 each. Everyone loves them, but most people aren’t seeing them for whatever reason. Can I add a prompt in checkout, almost like signing up for email subscription, that says “would you like to add  {product name} to your order?” And then when the box is checked it adds the item to their order?

[biznazz101]

You can either use an app, there are many OR

You can follow this guide, then use the checkout link in a "rich text" section button added to your cart page. If you are not using Shopify plus you will not be able to edit the actual checkout.