There are two ways to gain access to the Playstation Exclusive Fortnite Heroes.
1. Purchase a Fortnite Founder's Pack on the Playstation Network.
2. Buy a Physical Edition of Fortnite for the PS4 console.
Players who have already purchased a Founder's Pack on PC and are now playing on PS4 using the same Epic account, are not qualified to receive the PSN Exclusive Heroes. These still applies even another Founder's Pack is purchased via the PSN--we strongly advise against this in general, as the Founder's Pack content does not stack.
Additionally, these heroes cannot be granted by request.
The PSN exclusive pre-order items are treated like all other Founder's Pack items, which means that they are not granted until after the tutorial is complete. You will receive them after completing the Loot Llamas tutorial mission.
Please don't hesitate to reach out if you have any additional questions!