Currently, it was made that the VIP time an in game item that can be purchased with Kafra Points.
The VIP package offers, increased EXP, increased Drop rate, access to second storage and offline vending/buying scrolls. Probably in future the benefits will expand but this is what it offers right now.
Adding VIP is a straightforward process.
On Power UP page, simply buy points (WPE) using your preferred payment method, then convert WPE points to your account ID. While being In-game open Kafra shop to buy the VIP package. Note that the package is tradable and vendable.
If you require further clarification let us know