my canvas code is:

            saveBtn: function () {
                var saveBtn = '<img height="20" src="data:image/png" />'
                $("<span class='simple-paint-tooltip simple-paint-buttons simple-paint-save-btn'   title='Save canvas as image' />").appendTo($(".simple-paint-top-tools"));
                $(".simple-paint-save-btn").html(saveBtn).on("click", function () {
                    var browser = method.getBrowser();
                    if (browser == "IE" || browser == "Edge") {
                        var blob = method.canvas.msToBlob();
                        window.navigator.msSaveBlob(blob, 'Tooska_visit.png');
                    } else {
                        method.canvas.toBlob(function (blob) {
                            var objectUrl = URL.createObjectURL(blob);
                            var a = document.createElement('a');
                            a.href = objectUrl;
                            a.download = "Tooska_visit.png";
                            a.target = '_blank';
                            document.body.appendChild(a);
                            a.click();
                            document.body.removeChild(a);
                            window.URL.revokeObjectURL(objectUrl);
                        });
                    }
                });
            }

image save as a png file. I want save that in mysql database. How can I send data to mysql?