<?php
$data = $_POST;
if( isset($data['do_signup']) )
{
    $cart = R::dispense('shop');
    $cart -> name = $data['name'];
    $cart -> product = $data['product'];
    $cart -> price = $data['price'];
    R::store($cart);
    var_dump($data); die();
}
?>
<div id="cart" class="modal fade">
  <div class="shop">
    <div class="head">
      <h3>Оформлення замовлення</h3>
    </div>
    <form id="buy" method="POST" action="profile.php" >
      <label for="exampleInputEmail1">Ведіть П.І.П.:</label>
      <input type="user" class="form-control" id="user" name="name" required>
      <label for="product">Товар:</label>
      <input type="text" class="form-control" id="product" name="product"  readonly>
      <label for="price">Сума:</label>
      <input type="text" class="form-control" id="price" name="price" readonly>
      <button type="submit" name= "do_signup"class="btn btn-primary">Придбати</button>
    </form>
  </div>
</div>