[quote=@Azure Flame]
For Dynamax Adventure you have to go to the Max Lair and click invite.  You can do passcodes for it, but unlike Max Raid Battles, it won't appear on your y-comm.
[/quote]

I entered the code AceTrainerLiam used and got put in a different group. We managed to win, but none of the mons were shiny so I didn't take any of them.