Flarum\Core\Access\DiscussionPolicy::rename PHP Method

    public function rename(User $actor, Discussion $discussion)
    {
        if ($discussion->start_user_id == $actor->id) {
            $allowRenaming = $this->settings->get('allow_renaming');
            if ($allowRenaming === '-1' || $allowRenaming === 'reply' && $discussion->participants_count <= 1 || $discussion->start_time->diffInMinutes(new Carbon()) < $allowRenaming) {
                return true;
            }
        }
    }