ASP.NET MVC: The sign-in name or password does not match one in the Microsoft account system

Question

I wanted to fetch all files from the document library one of my Online Sharepoint site. For that, I have created 2 apps i.e. Console App and ASP.Net MVC apps

Below is the code,

using ASPNetDemo.Models;
using Microsoft.SharePoint.Client;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security;
using System.Web.Mvc;

namespace ASPNetDemo.Controllers
{
public class DocumentLibraryController : Controller
{

    private readonly string baseURL;
    private readonly string siteURL;

    public DocumentLibraryController()
    {
        baseURL = "https://onevirtualoffice.sharepoint.com";
        siteURL = $"{baseURL}/sites/mysite";
    }

    // GET: DocumentLibrary
    public ActionResult Index()
    {
        var model = new FileUploadViewModel();
        model.Username = "[email protected]";
        model.Password = "{password}";

        var list = GetFiles(model);// get all files from 

        return View();
    }

    public List<string> GetFiles(FileUploadViewModel model)
    {
        try
        {
            using (var clientContext = new ClientContext(siteURL))
            {
                SecureString passWordSecure = new SecureString();
                foreach (char c in model.Password.ToCharArray()) passWordSecure.AppendChar(c);
                clientContext.Credentials = new SharePointOnlineCredentials(model.Username, passWordSecure);

                Web web = clientContext.Web;

                #region get list

                List<string> fileList = new List<string>();

                var results = new Dictionary<string, IEnumerable<Microsoft.SharePoint.Client.File>>();
                var lists = clientContext.LoadQuery(clientContext.Web.Lists.Where(l => l.BaseType == BaseType.DocumentLibrary));
                clientContext.ExecuteQuery();
                foreach (var list in lists)
                {
                    if (list.Title.Equals("TestFolder"))
                    {
                        var items = list.GetItems(CreateAllFilesQuery());
                        clientContext.Load(items, icol => icol.Include(i => i.File));
                        results[list.Title] = items.Select(i => i.File);
                    }
                }
                clientContext.ExecuteQuery();

                foreach (var result in results)
                {
                    foreach (var file in result.Value)
                    {
                        var fileName = "";

                        if (string.IsNullOrEmpty(file.LinkingUri))
                            fileName = string.Concat(baseURL, file.ServerRelativeUrl);
                        else
                            fileName = file.LinkingUri;

                        fileList.Add(fileName);
                    }
                }

                return fileList;

                #endregion
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    private CamlQuery CreateAllFilesQuery()
    {
        var qry = new CamlQuery();
        qry.ViewXml = "<View Scope=\"RecursiveAll\"><Query><Where><Eq><FieldRef Name=\"FSObjType\" /><Value Type=\"Integer\">0</Value></Eq></Where></Query></View>";
        return qry;
    }
}
}

The above code is working fine in Console application and its fetching all the files under TestFolder document library. But When I tried the same code in ASP.Net MVC5 Framework 4.6.1 then it throwing an exception as The sign-in name or password does not match one in the Microsoft account system.

Could you please help to guide where I am wrong.