# Test adding a product coupon to the InLine Checkout

## Overview

Use the `TwoCoInlineCart.cart.addCoupon('COUPON')` method to apply a single coupon.

## Use case - add product coupon

1. Add an HTML link or button to your page like the one below.
2. Create a JavaScript click handler to execute the Inline Client desired methods.
3. Use the`TwoCoInlineCart.products.add({code, quantity, options})`method to prepare your catalog product.
4. To apply a coupon to your products in the shopping cart, use the`TwoCoInlineCart.cart.addCoupon('COUPON')`method.
5. To show the cart on your page call the`TwoCoInlineCart.cart.checkout()`method.

## Sample request

### HTML

```html
<a href="#" class="btn btn-success" id="buy-button">Buy now!</a>
```

### JavaScript

```javascript
window.document.getElementById('buy-button').addEventListener('click', function() {
  TwoCoInlineCart.products.add({
    code: "74B8E17CC0"
  });
  TwoCoInlineCart.cart.addCoupon('CUPON');
  TwoCoInlineCart.cart.checkout();
});
```

## Demo

After setting the test mode to add a coupon to the InLine checkout using the above method, your cart should look like this:

{% embed url="<https://codepen.io/2checkout-documentation/pen/WqGbEw>" %}


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