How to Export Data from Database Table to Excel File in Asp.net Core MVC

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "ConnectionStrings": {
    "sqlconnection": "Server=(local)\\MSSQL;Database=InventoryDB;Trusted_Connection=True;MultipleActiveResultSets=true"
    
  },
  "AllowedHosts": "*"
}

//Customer.cs

using System.ComponentModel.DataAnnotations;

namespace Asp.netcore_Tutorials.Models
{
    public class Customer
    {
        [Key]

        public int id { get; set; }
        public string firstName { get; set; }
        public string lastName { get; set; }
        public string job { get; set; }
        public float amount { get; set; }
        public DateTime tdate { get; set; }
    }
}

//CustDbcontext.cs
using Microsoft.EntityFrameworkCore;

namespace Asp.netcore_Tutorials.Models
{
    public class CustDbcontext :DbContext 
    {

        public CustDbcontext(DbContextOptions<CustDbcontext> options):base(options)
        {

        }

        public virtual DbSet<Customer> Customers { get; set; }
    }
}

using System.Data;

namespace Asp.netcore_Tutorials.Repository
{
      public interface IExportCustomer
    {
        DataSet ExportCustomerDataTable();
        DataTable ExportCustomer();
    }
}

using Microsoft.AspNetCore.Http;
using System.Data;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.IO;

namespace Asp.netcore_Tutorials.Repository
{
     public class ExportCust : IExportCustomer
    {
        private IConfiguration _configuration;

        public ExportCust(IConfiguration configuration)
        {
            _configuration = configuration;
        }
        public DataTable ExportCustomer()
        {
            DataTable Custdatatable = ExportCustomerDataTable().Tables[0];
            return Custdatatable;

        }
        public  DataSet ExportCustomerDataTable()
        {
            DataSet ds = new DataSet();
            var sqlconn = _configuration.GetConnectionString("sqlconnection");

            string getcustomer = "SELECT * FROM Customers";
            using (SqlConnection scon = new SqlConnection(sqlconn))
            {
                using (SqlCommand cmd = new SqlCommand(getcustomer))
                {
                    cmd.Connection = scon;
                    using (SqlDataAdapter sqlAdapter = new SqlDataAdapter(cmd))
                    {
                        sqlAdapter.Fill(ds);

                    }
                }
            }
            return ds;
        }
    }
}

using Asp.netcore_Tutorials.Models;
using Asp.netcore_Tutorials.Repository;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using System.Configuration;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();

builder.Services.AddDbContext<CustDbcontext>(conn => conn.UseSqlServer(builder.Configuration.GetConnectionString("sqlconnection")));  
builder.Services.AddScoped<ICustomer,CustomerDetail>();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();

app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

Add-Migration 'Initial-Create'
Update-Database

 using Asp.netcore_Tutorials.Repository;
using Microsoft.AspNetCore.Mvc;
using ClosedXML.Excel;
using System.Collections;

namespace Asp.netcore_Tutorials.Controllers
{
    public class ExportController : Controller
    {

        private readonly IExportCustomer _customer;
        public ExportController(IExportCustomer customer)
        {
            _customer= customer;
        }
        public IActionResult Index()
        {           
            return View();
        }

        [HttpPost]
        [AutoValidateAntiforgeryToken]
        public IActionResult ExporttoExcel()
        {
            var arraylist = _customer.ExportCustomer();

            using (XLWorkbook xl = new XLWorkbook())           
            {
                xl.Worksheets.Add(arraylist);  
                
                using (MemoryStream mstream = new MemoryStream())
                {
                    xl.SaveAs(mstream);
                    return File(mstream.ToArray(), "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "Customer.xlsx");
                }
            } 
        } 
    }
}

@{
    ViewData["Title"] = "Home Page";
}

<div class="row">
    <div class="col-5">

        <form method="post" enctype="multipart/form-data" asp-controller="Export" asp-action="ExporttoExcel">
             
            
            <div class="form-group">
                <div class="col-md-10">

                    <input class="btn btn-primary" type="submit" value="Export File" />

                </div>
            </div>
        </form>

         
    </div>
</div>