Custom Amounts

You can enable a custom amount for vouchers, which allows the customer purchasing the voucher to set its value. Enable the Custom amount? option in the control panel for the voucher you want to support this.

You'll also need to update your front-end templates to allow customers to enter an amount when adding the voucher to their cart:

{% if voucher.customAmount %}
    <input type="text" name="options[amount]" placeholder="Amount">
{% endif %}

For a full single voucher template example, see the Single Voucher guide.