$("#downloadButton").click(function () {
    var title = $("#productName").val();
    var description = $("#productDescription").val();
    var price = $("#productPrice").val();
    var urlImage = $("#productUrl").val();
    $.ajax({
        url: "/api/productgallery/",
        method: "POST",
        data: JSON.stringify({ title: title, description: description, price: price, urlImage: urlImage }),
        contentType: "application/json; charset=utf-8",
        success: function (result) {
            loadGallery("tblProductGallery", function () {
            });
        }
    })
});

<div class="col-4 productCard" id="pCard15">
    <img class="image" src="ссылка">
    <h1 class="titleText">123</h1>
    <p class="descriptionText">123</p>
    <p class="priceText">321$</p>
    <button class="btn btn-success changeProduct" id="changeProduct">Change Product</button>
  </div>