In the current version there is no "Add gift card" button in Marketing > Giftcards — the page only lists and edits cards that were created through a checkout, and its edit form only changes an existing card's recipient details. To give a customer stored value directly without a purchase:

1. Open the customer under Customers.
2. Click Edit Balance (shown next to their current balance; requires the "Edit Users - Digital Wallet" permission).
3. Enter an amount, choose Add balance, and save.

This credits the same digital wallet a redeemed gift card would. Alternatively, place the gift card order on the customer's behalf through the website.