Single amount per product (Simple Product)
You can optionally have a single, fixed amount for the gift card product so that the customer does not have to select the amount.
The PW Gift Card product type is an extension of the Variable Product type in WooCommerce. If you have the PW Gift Cards Pro version you can choose a default amount for the gift card product. Using this feature you can accomplish your goal by taking the following steps:
1. Create the PW Gift Card product with 1 fixed amount.
2. Set the “Default Amount” option to the fixed amount.
3. Hide the “Select an amount” dropdown menu by following these steps:
https://www.pimwick.com/pw-faq/hide-amount-selection-dropdown-menu/