foreach($users as $user){
    $array_user[] = ["field" => "tag", "key" => "id", "relation" => "=", "value" => $user->id];
    if ($i != $len - 1) {
        $usuarios_array[] = ['operator' => 'OR'];
    }
    $i++;            
}
$response = \OneSignal::sendNotificationUsingTags(
    "Some message",
    $array_user,
    $url = null,
    $data = null,
    $buttons = null,
    $schedule = null,
);