There are a few different approaches you can take to export Excel files using JavaScript. Here are some options:

1. Use a library like SheetJS: SheetJS is a JavaScript library that provides tools for working with spreadsheet files, including Excel files. You can use it to create, read, and write Excel files in JavaScript. To export an Excel file, you would use the writeFile function, like this:

const workbook = XLSX.utils.book_new();
const worksheet = XLSX.utils.json_to_sheet(data);
XLSX.utils.book_append_sheet(workbook, worksheet, 'Sheet1');
XLSX.writeFile(workbook, 'filename.xlsx');

2. Use the Blob object: Another way to export Excel files using JavaScript is to create a Blob object and then use the URL.createObjectURL method to create a download link. Here’s an example:

const wb = XLSX.utils.table_to_book(document.getElementById('myTable'));
const wbout = XLSX.write(wb, {bookType:'xlsx',  type: 'binary'});
const blob = new Blob([s2ab(wbout)],{type:"application/octet-stream"});
const fileName = "myExcelFile.xlsx";
const downloadLink = URL.createObjectURL(blob);
const a = document.createElement("a");
a.href = downloadLink;
a.download = fileName;
document.body.appendChild(a);
a.click();
setTimeout(function() {
  document.body.removeChild(a);
  window.URL.revokeObjectURL(downloadLink);  
}, 100);

3. Use a server-side script: Another option is to use a server-side script, like PHP or Python, to generate the Excel file and then download it using JavaScript. This approach can be more complex, but it allows you to generate more complex Excel files that may not be possible using just JavaScript.