Although you can purchase PlayerUnknown’s Battlegrounds on many places such as PlayStation Store, Steam or Microsoft Store. There are places that sell PUBG CD Keys. That being said we are not able to give you any links to where to get them because any source for CD keys are not 100% reliable. When you want to buy a CD key for PUBG on PC, PS4, and Xbox, you have to choose your seller very carefully. Most stores online sell these CD keys for a lower price than $29.99. Which is the price for PUBG on all official stores.
To pick the right seller you should check other comments to see if the store who sells it is reliable or not. Still, though we highly recommend that you buy it on PlayStation Store, Microsoft Store or Steam as these are the official sellers for PUBG on all major platforms.