How do you get Moo Moo Milk in the base game(not expansions)?

Eremas

I won an Auction for Moo Moo Milk and the NPC was saying they'll hold onto the item like I'll get to return with the money later. I come back after selling PokeBalls and Full Restores but cannot interact the right way! I don't play games for the realism! Let's add a way to get Moo Moo Milk for people buying the game! Plus making such a change would look good on NASDAQ! It gives 100Hp! I haven't seen any other classic items missing in the game like this nor heard of any others that are missed.

Please address this.

To Games Freak

From,

Eremas

Lonestar85

School store has it if im not mistaken. Need 6 Gym Badges for it to appear though.

Eremas

https://ibb.co/Kp65Yqkg

Here it is just like you said!