document.getElementById('xlsx').addEventListener('click', () => {

        pivotGrid.beginUpdate();
        pivotGrid.allowMerging= false;

        // create book with current view
        let book = wijmo.grid.xlsx.FlexGridXlsxConverter.saveAsync(pivotGrid, {
            includeColumnHeaders: true,
            includeRowHeaders: true,
            saved:()=>{
               pivotGrid.allowMerging= true;
               pivotGrid.endUpdate();
            }
        });
        book.sheets[0].name = 'PivotGrid';
        // save the book
        book.saveAsync('PivotGrid.xlsx');
         
    });