The PlayStation Store allows you to purchase gift cards, but because it’s an entirely online store, you have to activate the cards with a code first.
This can easily be done from your PlayStation 4 if it has a connection to the internet.
Check out the products mentioned in this article:
PlayStation 4 (From $299.99 at Best Buy)
How to redeem a gift card code on your PS4
1. Log into your account on your PS4 and access the PlayStation Store. This should be a registered account with internet access.
2. From the PlayStation 4’s Store menu, scroll down to the second-to-last option, “Redeem Codes,” and select it.