How do you use the mystery event button in Pokemon sapphire?

The mystery event button in Pokemon Sapphire allows you to connect using the Game Boy Advance wireless adapter or the link cable. It allows players to receive **events Pokemon and items by connecting to local event distributions*. It can be found in the menu accessible by *pressing the Start button in-game*. Note that this button was used primarily during the time when the game was originally released and may not be fully operational due to the changes in Nintendo's online services over time.