You can check PSN Codes from this link and order it now depending on your country region to buy VBucks.
Purchase 20 GBP PSN Card to get 2500 Fortnite (+300 Bonus!) V-Bucks . This in-game currency can be spent in both the Battle Royale PvP mode and the Save the World PvE campaign. In Battle Royale you can purchase new customization items for your Hero, glider, or pickaxe. In Save the World you can purchase Llama Pinata card packs that contain weapon, trap and gadget schematics as well as new Heroes and more! Note: Items do not transfer between the Battle Royale mode and the Save the World campaign.