Classe pronta para consumir a API. Substitua SUA_CHAVE_AQUI pela sua chave, disponivel na pagina da conta.

<?php

class EixodsmmApi
{
    public $api_url = 'https://eixodsmm.com/api/v2';
    public $api_key = 'SUA_CHAVE_AQUI';

    // Lista de servicos
    public function services() {
        return $this->connect(['key' => $this->api_key, 'action' => 'services']);
    }

    // Adicionar pedido
    public function order($data) {
        $post = array_merge(['key' => $this->api_key, 'action' => 'add'], $data);
        return $this->connect($post);
    }

    // Status de um pedido
    public function status($order_id) {
        return $this->connect([
            'key'    => $this->api_key,
            'action' => 'status',
            'order'  => $order_id,
        ]);
    }

    // Status de varios pedidos
    public function multiStatus($order_ids) {
        return $this->connect([
            'key'    => $this->api_key,
            'action' => 'status',
            'orders' => implode(',', (array) $order_ids),
        ]);
    }

    // Saldo
    public function balance() {
        return $this->connect(['key' => $this->api_key, 'action' => 'balance']);
    }

    private function connect($post) {
        $_post = [];
        if (is_array($post)) {
            foreach ($post as $name => $value) {
                $_post[] = $name . '=' . urlencode($value);
            }
        }

        $ch = curl_init($this->api_url);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, implode('&', $_post));
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30);
        $result = curl_exec($ch);

        if (curl_errno($ch) != 0 && empty($result)) {
            $result = false;
        }
        curl_close($ch);

        return json_decode($result, true);
    }
}

// ---- Exemplo de uso ----
$api = new EixodsmmApi();

$servicos = $api->services();

$pedido = $api->order([
    'service'  => 1,
    'link'     => 'https://instagram.com/seu_perfil',
    'quantity' => 100,
]);

$status = $api->status($pedido['order']);
$saldo  = $api->balance();