<script src="https://cdn.jsdelivr.net/gh/linways/table-to-excel@v1.0.4/dist/tableToExcel.js"></script>


<button id="btnExport" onclick="exportReportToExcel(this)">EXPORT REPORT</button>

function exportReportToExcel() {
  let table = document.getElementsByTagName("table"); // you can use document.getElementById('tableId') as well by providing id to the table tag
  TableToExcel.convert(table[0], { // html code may contain multiple tables so here we are refering to 1st table tag
    name: `export.xlsx`, // fileName you could use any name
    sheet: {
      name: 'Sheet 1' // sheetName
    }
  });
}