How to switch to api vk correctly?

Question

PHP

after VK stopped supporting versions of api 3.0 and 4.0, the VK dynamic cover script stopped working, it displayed the last person who joined the group and the user who put more likes for a certain period of time, with the new one it turned out to find a solution, but with the "liker" no..(( returns incorrect answer: ok[ ]
what's wrong here?

public function getLikerId()
    {
        global $config;

        $users = [];

        $time_to = time();
        if (!empty($config['like_interval']['to'])) {
            $time_to = strtotime($time_to);
        }

        $posts = $this->getPosts(-$config['group_id']);

        foreach ($posts as $post) {
            if ($post->date < strtotime($config['like_interval']['from']) || $post->date > $time_to) {
                continue;
            }

            $likes = $this->getLikes(-$config['group_id'], $post->id);

            foreach ($likes->users as $id) {
                if (isset($users[$id])) {
                    $users[$id]++;
                } else {
                    $users[$id] = 1;
                }
            }
        }

        arsort($users);
        $user_ids = array_keys($users);
        $user_id = array_shift($user_ids);
        return $user_id;
    }

    /**
     * Getting posts
     * @param integer $owner_id - owner post id
     * @param integer $count - count posts
     * @return object - vk posts array
     */
    private function getPosts($owner_id = 1, $count = 100)
    {
        $res =  $this->api('wall.get', [
            'owner_id' => $owner_id,
            'count'   => $count,
            ]);
        return $res;
    }

    /**
     * Getting likes for post
     * @param integer $owner_id - owner post id
     * @param integer $item_id - post id
     * @param string $type - type
     * @return object - vk likes array
     */
    private function getLikes($owner_id = 1, $item_id = 1, $type = 'post')
    {
        return $this->api('likes.getList', [
            'owner_id' => $owner_id,
            'item_id'   => $item_id,
            'type'   => $type,
            ]);
    }