You can use Target or Vanilla gift cards just make sure that they come with either MasterCard or Visa or any other major gateway provider.
The methods for Target and Vanilla Gift cards are the same as you add your Credit or Debit card to the PlayStation Store Payment method.
You can use the Walmart Gift card at all Walmart online and offline stores, Walmart-owned retailers, and selected Fuel Stations only. Unfortunately, you Can't use them on PlayStation.
Apple Gift card is designed to buy Apple products and services like iTunes, iBooks, App Store, Podcasts, etc. So, you can use them to buy Books, Music, Apps, Podcasts, etc.