Starting on July 3rd, 2021, the Pokémon Card Gym - Promo Card Pack Vol. 6 will be available to players that win battles at an authorized Pokémon Card Gym in Japan.
This Pokémon Card Gym exclusive Momi Holo Promo Card can be obtained by battling with four or more Pokémon with the "E" regulation mark! The Pokémon Card Gym-only campaign cards are stamped with a Pokémon Card Gym logo. You'll get a random card from a total of eight card, including Kinogassa V and Dogas!
Source:
https://www.pokemon-card.com/info/2021/20210625_002992.html