From April 1st through May 1st you will be able to receive the Members Card through Mystery Gift in Pokémon Brilliant Diamond and Shining Pearl to encounter Darkrai
https://twitter.com/SerebiiNet/status/1503719482082136074?s=20&t=1u-06Lc0trKd9Fd0etxZ0A
@sachirin niice. I hope i remember to get this