This event gives trainers the chance to get their hands on Color Statues of Turtwig, Chimchar and Piplup which can be placed in your Secret Base within the Grand Underground. To access the Mystery Gift you'll need to enter the code: BDSPUNDERGR0UND
The event runs until the 31st of May 2022, so plenty of time for you to pick it up. Especially those of you who may not get your hands on the games until Christmas!