Auto-assign offers a newly posted fixture to the closest available referee automatically, without a League administrator having to work through the fixture list by hand. It's available on Pro and Plus plans; Starter fixtures are always assigned manually.
1. There's no separate toggle
Auto-assign isn't a setting you switch on. Every fixture posted under a Pro or Plus Association is automatically considered for auto-assignment the moment it's created, both the primary referee and any additional officiating roles (see adding assistant referees) the category needs. If your plan is Starter, upgrade from the Billing tab and new fixtures posted afterward will be auto-assigned.
2. How a candidate is chosen
The closest referee, by travel distance from their base location, whose own travel radius covers the fixture and who has no conflicting assignment within two hours of the fixture's start time, is offered the fixture. If a referee has set which sport(s) they officiate, only fixtures in one of those sports are considered; if they haven't set a preference, or the Association hasn't recorded a sport, matching stays distance-only.
3. When nothing gets assigned
If no referee within radius is free, the fixture is simply left Open and appears on the dashboard's coverage-gap summary for manual attention, the same as it would if auto-assign weren't available at all.
4. Referees can still decline
Auto-assign offers a fixture; it doesn't force anyone to take it. An assigned referee can withdraw, which reopens the fixture, and since auto-assign only runs once, at the moment a fixture is created, a reopened fixture needs manual assignment from the dashboard.