[HttpGet("exportexcell")]
    public async Task<FileContentResult> ExportExcel()
    {
        var loggedUser = await GetCurrentUserAsync();
        var users = _userManager.Users.Select(u => new UserListVM
        {
            Id = u.Id,
            Name = u.UserName,
            Email = u.Email
        }).ToList();

        if (users == null) return null;

        //column Header name
        var columnsHeader = new List<string>{
            "S/N",
            "User Name",
            "Email"
        };
        var filecontent = ExportExcell(users, columnsHeader, "Users");
        return File(filecontent, "application/ms-excel", "users.xlsx"); ;
    }

private static byte[] ExportExcell(List<UserListVM> data, List<string> columns, string heading)
    {
        byte[] result = null;

        using (ExcelPackage package = new ExcelPackage())
        {
            // add a new worksheet to the empty workbook
            var worksheet = package.Workbook.Worksheets.Add(heading);
            using (var cells = worksheet.Cells[1, 1, 1, 7])
            {
                cells.Style.Font.Bold = true;
                cells.Style.Fill.PatternType = ExcelFillStyle.Solid;
                cells.Style.Fill.BackgroundColor.SetColor(Color.Green);
            }
            //First add the headers
            for (int i = 0; i < columns.Count(); i++)
            {
                worksheet.Cells[1, i + 1].Value = columns[i];
            }

            //Add values
            var j = 2;
            var count = 1;
            foreach (var item in data)
            {
                worksheet.Cells["A" + j].Value = count;
                worksheet.Cells["B" + j].Value = item.Name;
                worksheet.Cells["C" + j].Value = item.Email;
                worksheet.Cells["D" + j].Value = item.RoleNam

                j++;
                count++;
            }
            result = package.GetAsByteArray();
        }

        return result;
    }

//First add the headers
for (int i = 0; i < dataList.Count; i++)
{
   worksheet.Cells[1, i + 1].Value = dataList[i];
}

//First add the headers
for (int i = 0; i < columnsHeader.Count; i++)
{
   worksheet.Cells[1, i + 1].Value = columnsHeader[i];
}