PlayStation Store gift cards are currently on offer through Instant Gaming, according to the promotional article. The top-up cards can be used to add funds to a PlayStation account, which can then be spent on content available in the store.
The article says the credit could be used to buy games, subscriptions and expansions, or to take advantage of Black Friday discounts. It also mentions Grand Theft Auto 6 as a possible use for the funds.
After purchasing a card, customers receive a code by email. Redeeming it adds the corresponding amount to their PlayStation Store balance.
Sources: Everyeye.it.