For anyone who signed up for the Pokémon Trainers Club newsletter last month in order to receive a Dada Zarude and Shiny Celebi Mystery Gift, you may want to pay a close eye to your emails. The Pokémon Company has begun distributing codes for both Mythical Pokémon via email.

If you find the email in your inbox, you can use the codes in the Mystery Gift Menu in Pokémon Sword/Pokémon Shield. Select the “Get With Code/Password” option and then input the codes. You should now be the proud owners of Dada Zarude and Shiny Celebi and just in time for Pokémon: Secrets Of The Jungle on Netflix too!
Source: The Pokémon Company (email)