I have call this api on button click with send static data but it's not call this error 
Failed to load resource: the server responded with a status of 400 ()
function planDetailModal() {
    var SubscriptionID = "Test";
    UpdateSubscription(SubscriptionID);
}
function UpdateSubscription(SubscriptionID) {
    debugger;
    var data = new FormData();
    data.UserID = "12Ggg";
    data.Criteria = {
        SubscriptionID: "Test",
        Create:
        {
            PaymentToken: "test",
            CustomerId: "Test"/*$("#customerId").val()*/,
            PriceId: "Testing" /*$("#priceID").val()*/
        }
    };
    var apiurl = paymentApiUrl + "api/Subscription/UpdateSubscription";
    //$(".messagePopup").show();
    //Loader();
    //$("#myModal").hide();
    $.ajax({
        type: 'POST',
        url: apiurl,
        data: JSON.stringify(data),
        datatype: "json",
        contentType: 'application/json; charset=UTF-8',
        success: function (response) {
            debugger;
            if (response.isSuccess == true) {
            }
        },
        error: function (response) {
            // console.log("Error => " + response);
            $.notify("there has been some error, please try again later !", "error");
            //$(".messagePopup").hide();
            //setTimeout(
            // reload
            // , 1500);
        }
    })
}