Edit in JSFiddle

// myjson PUT Example
// 1. Create valid uri via POST
// 2. Update data via PUT

var obj = {
    "key": "value",
    "key2": "value2"
};
var data = JSON.stringify(obj);

$("#clickMe").click(function () {
    $.ajax({
        url: "https://api.myjson.com/bins",
        type: "POST",
        data: data,
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (data, textStatus, jqXHR) {
            
            var updatedObj = {
                "key": "updated value",
                "key2": "updated value2"
            };
            var updatedData = JSON.stringify(updatedObj);

            // do update
            $.ajax({
                url: data.uri,
                type: "PUT",
                data: updatedData,
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (data, textStatus, jqXHR) {
                    var json = JSON.stringify(data);
                    $("#data").val(json);
                }
            });
        }
    });
});

<textarea id="data" rows="5" cols="40"></textarea>
<br />
<input id="clickMe" type="button" value="PUT Example" />