> For the complete documentation index, see [llms.txt](https://docs.giftcardfactory.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.giftcardfactory.app/extensions/gift-card-custom-amount.md).

# Gift Card Custom Amount

Let shoppers enter their own gift card amount on the product page.

Gift Card Custom Amount is a **cart transform function**. When a shopper picks the **Custom** denomination on your app gift card product and types an amount, the function prices that cart line at exactly the amount entered. It replaces the deprecated Shopify Script the app used before.

[Watch the demo](https://gcf-cdn.s3.us-east-2.amazonaws.com/videos/gift-card-custom-value.mp4)

{% hint style="warning" %}
Cart transform price updates run on **Shopify Plus** and development stores only. On other plans the option is not shown and shoppers choose from the fixed denominations you sell.
{% endhint %}

## Turning it on

There is nothing to place. Open your Gift Card Postman campaign, turn on **Enable custom gift card value** and save. The app registers the function for you and removes it again when no active Postman campaign uses custom values. The Extensions page shows it as **Active** or **Off**.

Set a maximum custom amount and the default value in the campaign settings. See [Gift Card Postman → Setup](/campaigns/gift-card-postman/setup.md#custom-gift-card-value).