exceljs.html

<script src="http://cdn.jsdelivr.net/g/filesaver.js"></script>
<script src="https://cdn.jsdelivr.net/npm/exceljs@4.3.0/dist/exceljs.min.js" integrity="sha256-wJUdjGj95YIQF7RrY8E0M/aU998QyfG6xYKtQLp05/I=" crossorigin="anonymous"></script>
<script>
    function SaveAsFile(t,f,m) {
        try {
            var b = new Blob([t],{type:m});
            saveAs(b, f);
        } catch (e) {
            window.open("data:"+m+"," + encodeURIComponent(t), '_blank','');
        }
    }
    
    async function saveAsExcel() {
        const wb = new ExcelJS.Workbook()

        const ws = wb.addWorksheet()

        const row = ws.addRow(['a', 'b', 'c'])
        row.font = { bold: true }

        const buf = await wb.xlsx.writeBuffer()
        
        SaveAsFile(buf,"abc.xlsx","application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
    }

</script>