EJ2 Data Grid Checkbox Selection

Question

I have an EJ2 data grid code in Javascrpt. I have checkboxes to select 1 to many rows. Upon selecting a row(s), how do I get the "Id" of those rows? Below is my grid definition.

        var grid = new ej.grids.Grid({
            dataSource: @Html.Raw(JsonConvert.SerializeObject((Model), new JavaScriptDateTimeConverter())),
            allowExcelExport: true,
            allowTextWrap: true,
            allowPdfExport: true,
            toolbar: ['ExcelExport', 'PdfExport', 'CsvExport'],
            //editSettings: { allowDeleting: true },
            allowSelection: true,
            allowFiltering: true,
            allowSorting: true,
            allowNumberFormatting: true,
            enableVirtualization: true,
            filterSettings: { type: 'Excel' },
            selectionSettings: { persistSelection: true },
            enableHover: true,
            enableHeaderFocus: true,
            height: 600,
            rowHeight: 38,
            allowPaging: true,
            columns: [
                { type: 'checkbox', width: 10 },
                { field: "Id", visible: false, isPrimaryKey: true},
                { field: "RegistarName",              headerText: "Registrar",         width: 50,},
                { field: "VoterStatus",               headerText: "Voter Status",      width: 50,},
                { field: "strTrainedDate",            headerText: "Trained",           width: 50,},
                { field: "strOathDate",               headerText: "Oath",              width: 50,},
                { field: "Term",                      headerText: "Term",              width: 50,},
                { field: "OrganizationTypeName",      headerText: "Organization Type", width: 50,},
                { field: "RegistrarOrganizationName", headerText: "Organization",      width: 50,},
                {
                    headerText: "",
                    template: "#editTemplate",
                    textAlign: "center",
                    width: 15
                },
                {
                    headerText: "",
                    template: "#deleteTemplate",
                    textAlign: "center",
                    width: 15
                },
            ],
        });