Change the generated number format and/or length

The auto-generated numbers are random for security purposes to keep people from guessing the numbers. Also, when an invalid gift card number is entered into the site, there is a “tar pit” of 5 seconds. This makes it nearly impossible for someone to brute-force guess a gift card number.

The auto-generated codes are 4 sets of 4 characters. If necessary, you can tweak the auto-generated gift card codes by following these steps:

1. Download the wp-config.php from your FTP server.
2. Keep a backup of wp-config.php in case there are problems.
3. Edit wp-config.php and scroll to the end and add the following bit of code:

Scroll towards the bottom, and before the line that says “Happy blogging.” add this code ABOVE that line (change the values as needed):

define( 'PWGC_RANDOM_CARD_NUMBER_SECTIONS', '4' );
define( 'PWGC_RANDOM_CARD_NUMBER_SECTION_LENGTH', '4' );
define( 'PWGC_RANDOM_CARD_NUMBER_CHARSET', 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789' );

/* That's all, stop editing! Happy blogging. */

4. Change the values for the settings as you see fit. We default to 4 sections that are 4 characters each.
5. Save the wp-config.php file and re-upload it to your server.

If you have any problems, replace wp-config.php with your backup file.

To add a prefix or a suffix to the randomly generated number, follow the steps in this guide:
https://www.pimwick.com/pw-faq/prefix-or-suffix-to-the-generated-numbers/