Scheduled gift cards
The gift cards are scheduled to be delivered after midnight using the WordPress Cron system.
You can find out more about the WordPress Cron system here:
https://developer.wordpress.org/plugins/cron/
With that said, ensure that the Order status is “Complete”. Gift Card numbers are generated and emailed only when the order status is Complete.
If the status is Complete, check your configured timezone by clicking on Settings -> General -> Timezone.