Laravel Sync Pivot Table with Third Column

Laravel’s official documentation about many to many sync states the following on syncing a third table value.

$user->roles()->sync([1 => ['expires' => true], 2, 3]);

How do you actually get those values however?

foreach ($group as $group) { 
    //collect all the ids 
    $pivot[$group->id] = ['type' => 'great']; 
} 
//Insert into user table 
$user->groups()->sync($pivot);