Use the Attach Activity to League/Tournament function to attach an activity to a league or tournament. Do this function if you want your customers to register for the league/tournament by registering for the activity.
The Attach Activity to League/Tournament function only appears for child leagues/tournaments that have no activities attached. If there is an activity attached to the child league/tournament, the Detach Activity from League function is available instead.
You can use the Detach Activity from League/Tournament function to detach an activity from a league or tournament. Do this if, for example, the incorrect activity was originally attached to the league/tournament.
Note that the Attach/Detach Activity functions only appear for child leagues/tournaments.
Note: You must attach an activity to a league before you can add customers to the league.
Go to Administration > League Settings > Leagues.
Search for and select a league or tournament.
Click Attach Activity to League/Tournament or Detach Activity from League/Tournament.
Note: The page names below depends on whether a league or tournament has been selected for editing.
From the Activity
Search page, you can click the binocular icon 
to search for the activity to attach to the league/tournament, which open
another detailed Activity Search
page.
Note that if a league/tournament has teams set up, you may not attach an activity that also has teams set up.
When detaching the activity, if you have set up the activity for team enrollment, then all teams belong to the activity after the detachment. However, if you have not set up the activity for team enrollment, then all teams belong to the league after the detachment. In either case, players are removed and enrollment transactions are updated to clear the team assignments.