Magento Commerce, 2.2.x
Configuring Gift Card Accounts

The Gift Card configuration establishes the default settings for all gift cards for the store view, and manages the code pool. The code pool is a set of unique gift card codes in a specific format. Codes from the pool are used each time a gift card account is created. It is the responsibility of the store administrator to ensure that there are enough codes available for gift card sales. Make sure to generate a code pool before offering gift cards for sale. By default, Magento generates 1,000 codes. A new pool is not generated until there are no more codes available in the current pool.