For full details about this event, see this page:
https://agoners.wordpress.com/2019/09/06/euro-strike/

Be sure that your Challonge name is the same name as your in-game name in Fantasy Strike. If your Discord name is different too, put your Discord name in parenthesis when registering for the tournament on Challonge

To play during the event, you will need to be available during the tournament both in game, and in the Agoners discord channel.