Redeemed in-game. Almost a freebie.

Source.

Rotating 1 PokéCoin bundles in the shop! New 1 PokéCoin bundles will be available in the shop each week as one-time purchases. The contents of these bundles change weekly, so be sure to get what is available each week. Right now, a new 1 PokéCoin bundle is available for you that contains the following.