<?php







// ao invés de multiplicar as dimensões pela quantidade, podes passar a quantidade do item conforme abaixo
$products = [
    //produto 1
    [
        'weight' => 1,
        'width' => 10,
        'height' => 10,
        'length' => 10,
        'quantity' => 3, // quantidade desse produto
        'insurance_value' => 50 // valor da unidade do produto
    ],
    //produto 2
    [
        'weight' => 0.5,
        'width' => 15,
        'height' => 15,
        'length' => 15,
        'quantity' => 2,
        'insurance_value' => 50
    ]
];


//$products = $this->cart->getProducts();
//$peso = $this->cart->getWeight(); // Peso

$me_products = [];
foreach ($products as $product) {
    $me_products[] = array(
            'weight' => $product['weight'],
            'width' => $product['width'],
            'height' => $product['height'],
            'length' => $product['length'],
            'quantity' => $product['quantity'],
            'insurance_value' => $product['insurance_value']
        );
}


$to_cep = '96055040';
$to_address = 'Rua teste';
$to_number = '123';

$body = array(
        'from' => [
            'postal_code' => '01032000',
            'address' => 'Rua brigadeiro tobias',
            'number' => '356',
        ],
        'to' => [
            'postal_code' => $to_cep,
            'address' => $to_address,
            'number' => $to_number,
        ],
        'products' => $me_products,
        'options' => [
            'receipt' => false,
            'own_hand' => false,
            'collect' => false
        ],
        'services' => "1,2,4"
    );

echo "<pre>";
print_r($body);

$curl = curl_init();
curl_setopt_array($curl, array(
  CURLOPT_URL => "https://melhorenvio.com.br/api/v2/me/shipment/calculate",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode($body),
  CURLOPT_HTTPHEADER => array(
    "Accept: application/json",
    "Authorization: Bearer TOKEN",
    "Cache-Control: no-cache",
    "Content-Type: application/json",
    "Postman-Token: b4d19c58-1d6b-a653-f225-dc0d719f1d3f"
  ),
));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  //echo $response;
}

//Decodificação pela função json_decode
$objeto_php = json_decode($response);

print_r($objeto_php);