The Pokémon Company will be holding an event called Battle with your Deck - Get Eievui (デッキそのままバトル～イーブイゲットだぜ～) at Pokémon Card Gyms all over Japan starting on Wednesday, July 21st, 2021. Bring or buy the required deck(s) in order to get the promo cards.

Event Details:

Date & Time: Starts on Wednesday, July 21st, 2021, while supplies last
Location: Pokémon Card Gyms throughout Japan
Conditions for Participation - Eligible Products: V-Start Decks (9 types), Decks from the Family Pokémon Card Game (3 types), Decks from the Anytime, Anywhere Family Pokémon Card Game (2 types)
Participation Prize: Eievui Promo card 100/S-P
Rock-Paper-Scissors Prize: Eievui VMAX Promo card 101/S-P

Source: https://www.pokemon-card.com/info/2021/20210721_003040.html