The DevExpress.excelExporter.exportPivotGrid function is based on the ExcelJS library. In the 20.1 release, this function is at the CTP stage and some behavior is not implement yet.
ExcelJS library allows exporting data in the CSV format as follows:
JavaScriptonExporting: function(e) {
DevExpress.excelExporter.exportPivotGrid({
component: e.component,
worksheet: worksheet
}).then(function() {
// https://github.com/exceljs/exceljs#writing-csv
// https://github.com/exceljs/exceljs#reading-csv
workbook.csv.writeBuffer().then(function(buffer) {
saveAs(new Blob([buffer], { type: "application/octet-stream" }), "Report.csv");
});
});
e.cancel = true;
},
See writing-csv, reading-csv, PivotGrid.ExcelJS export - How to export PivotGrid to CSV for more details.