u/BeaconToTheAngels

I just noticed this coin in my inventory. When I googled, it said I need 999 to be able to evolve Gimmghoul! Neither of the Gimmighouls I have have the option to evolve. Once I get the coins, will that appear? How do I get the coins? My search said I need to send postcards to another Pokémon game that I don’t have.