Get Identity Role id - ASP.NET Core MVC

Question

I am new to ASP.NET Core MVC, and I'm trying to develop a popup modal for Edit and Create. The create popup works, but when it comes to edit I can't get the id for role, in the controller the id comes as null. The delete method works too, only the edit doesn't work. Also when I save the data the view doesn't load the table, I have to refresh the page in order to view the data.

RoleController.cs

using GoldenHands.Data;
using GoldenHands.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.EntityFrameworkCore;
using System;
using System.Linq;
using System.Threading.Tasks;

namespace GoldenHands.Controllers
{
    public class RoleController : Controller
    {
        RoleManager<IdentityRole> _roleManager;
        UserManager<IdentityUser> _userManager;
        ApplicationDbContext _db;

        public RoleController(RoleManager<IdentityRole> roleManager, UserManager<IdentityUser> userManager, ApplicationDbContext db)
        {
            _roleManager = roleManager;
            _userManager = userManager;
            _db = db;
        }

        public IActionResult Index()
        {
            var roles = _roleManager.Roles.ToList();
            ViewBag.Roles = roles;
            return View();
        }

        // GET: Role/AddOrEdit
        // GET: Role/AddOrEdit/5
        public async Task<IActionResult> AddOrEdit(int id = 0)
        {
            if (id == 0)
            {
                return View(new IdentityRole());
            }
            else
            {
                var role = await _db.Roles.FindAsync(id);
                if (role == null)
                {
                    return NotFound();
                }
                return View(role);
            }
        }

        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> AddOrEdit(string id, string name)
        {
            IdentityRole role = new IdentityRole();

            if (ModelState.IsValid)
            {
                if (id == null)
                {
                    //_db.Add(identityRole);
                    //await _db.SaveChangesAsync();
                    role.Name = name;
                    var isExist = await _roleManager.RoleExistsAsync(role.Name);
                    if (isExist)
                    {
                        ViewBag.mgs = "This role is aldeady exist";
                        ViewBag.name = name;
                    }
                    var result = await _roleManager.CreateAsync(role);
                    if (result.Succeeded)
                    {
                        TempData["save"] = "Role has been saved successfully";
                    }
                }
                else
                {
                    try
                    {
                        role = await _roleManager.FindByIdAsync(id);
                        if (role == null)
                        {
                            return NotFound();
                        }
                        role.Name = name;
                        var isExist = await _roleManager.RoleExistsAsync(role.Name);
                        if (isExist)
                        {
                            ViewBag.mgs = "This role is aldeady exist";
                            ViewBag.name = name;
                        }
                        var result = await _roleManager.UpdateAsync(role);
                        if (result.Succeeded)
                        {
                            TempData["save"] = "Role has been updated successfully";
                        }
                    }
                    catch (DbUpdateConcurrencyException)
                    {
                        return NotFound();
                        //if (!ex(identityRole.Id))
                        //{
                        //    return NotFound();
                        //}
                        //else
                        //{
                        //    throw;
                        //}
                    }
                }
                return Json(new { isValid = true, html = Helper.RenderRazorViewToString(this, "_RoleTablePartialView", _roleManager.Roles.ToList())});

            }
            return Json(new { isValid = false, html = Helper.RenderRazorViewToString(this, "AddOrEdit", role) });
        }

        public async Task<IActionResult> Delete(string id)
        {
            var role = await _roleManager.FindByIdAsync(id);
            if (role == null)
            {
                return NotFound();
            }
            ViewBag.id = role.Id;
            ViewBag.name = role.Name;
            return View();
        }

        [HttpPost]
        [ActionName("Delete")]
        public async Task<IActionResult> DeleteConfirm(string id)
        {
            var role = await _roleManager.FindByIdAsync(id);
            if (role == null)
            {
                return NotFound();
            }

            var result = await _roleManager.DeleteAsync(role);
            if (result.Succeeded)
            {
                TempData["delete"] = "Role has been deleted successfully";
                return RedirectToAction(nameof(Index));
            }
            return View();
        }

        public async Task<IActionResult> Assign()
        {

            ViewData["UserId"] = new SelectList(_db.ApplicationUsers.Where(f => f.LockoutEnd < DateTime.Now || f.LockoutEnd == null).ToList(), "Id", "UserName");
            ViewData["RoleId"] = new SelectList(_roleManager.Roles.ToList(), "Name", "Name");
            return View();
        }

        [HttpPost]
        public async Task<IActionResult> Assign(RoleUserVm roleUser)
        {
            var user = _db.ApplicationUsers.FirstOrDefault(c => c.Id == roleUser.UserId);
            var isCheckRoleAssign = await _userManager.IsInRoleAsync(user, roleUser.RoleId);
            if (isCheckRoleAssign)
            {
                ViewBag.mgs = "This user already assign this role.";
                ViewData["UserId"] = new SelectList(_db.ApplicationUsers.Where(f => f.LockoutEnd < DateTime.Now || f.LockoutEnd == null).ToList(), "Id", "UserName");
                ViewData["RoleId"] = new SelectList(_roleManager.Roles.ToList(), "Name", "Name");
                return View();
            }
            var role = await _userManager.AddToRoleAsync(user, roleUser.RoleId);
            if (role.Succeeded)
            {
                TempData["save"] = "User Role assigned.";
                return RedirectToAction(nameof(Index));
            }
            return View();
        }

        public ActionResult AssignUserRole()
        {
            var result = from ur in _db.UserRoles
                         join r in _db.Roles on ur.RoleId equals r.Id
                         join a in _db.ApplicationUsers on ur.UserId equals a.Id
                         select new UserRoleMaping()
                         {
                             UserId = ur.UserId,
                             RoleId = ur.RoleId,
                             UserName = a.UserName,
                             RoleName = r.Name
                         };
            ViewBag.UserRoles = result;
            return View();
        }
    }
}

Index.cshtml

@model IEnumerable<ApplicationUser>
@using GoldenHands.Models;

@{
    ViewData["Title"] = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<br />
<br />
<br />
<div class="row">
    <div class="col-6">
        <h3 class="titulli1">Role list</h3>
    </div>
    <div class="col-6 text-end">
        <a onclick="showInPopup('@Url.Action("AddOrEdit","Role",null,Context.Request.Scheme)','Add New')" class="butoni">+ Add New</a>
    </div>
</div>
<br />
<div id="view-all">
    @await Html.PartialAsync("_RoleTablePartialView", Model)
</div>

AddOrEdit.cshtml

@*@model IEnumerable<ApplicationUser>*@
@{
    ViewData["Title"] = "Edit";
    Layout = null;
}
<form asp-action="AddOrEdit" asp-route-id="@ViewBag.id" onsubmit="return jQueryAjaxPost(this)" autocomplete="off" class="forma">
    <div class="p-4 rounded">
        <div asp-validation-summary="ModelOnly" class="text-danger"></div>

        <h3>@ViewBag.mgs</h3>
        <div class="form-group row">
            <div class="col-4 text-end">
                <label class="input-labela">Role Name:</label>
            </div>
            <input type="hidden" value="@ViewBag.id" name="id" />

            <div class="col-7">
                <input id="name" name="name" required="required" value="@ViewBag.name" class="inputi" />
            </div>
        </div>

        <br />
        <div class="form-group">
            <a asp-action="Index" class="butoni">Cancel</a>
            <input type="submit" class="butoni" value="Save" />
        </div>
    </div>
</form>

RoleTablePartialView.cshtml

<table class="tabela">
    <tr class="">
        <th class="tabela-header">Name</th>
        <th class="tabela-header"></th>
    </tr>
    @foreach (var item in ViewBag.Roles)
    {
        <tr>
            <td>@item.Name</td>
            <td style="width: 150px">
                <div class="btn-group">
                    <!--EDIT-->
                    <a onclick="showInPopup('@Url.Action("AddOrEdit","Role", new { id = item.Id },Context.Request.Scheme)',' Edit')" class="butoni tooltipi">
                        <img src="~/images/edit.png" class="photo" alt="edit">
                        <span class="tooltipitext">Edit</span>
                    </a>

                    <!--DELETE-->
                    <form asp-action="Delete" asp-route-id="@item.Id" method="post" id="deletebutoni">
                        <button type="submit" class="butoni tooltipi" onclick="return functionConfirm(this)">
                            <img src="~/images/delete.png" class="photo" alt="delete"><span class="tooltipitext">Delete</span>
                        </button>
                    </form>
                </div>
            </td>
        </tr>
    }
</table>

My modal in Layout.cshtml

    <div class="modal" tabindex="-1" role="dialog" id="Popup-modal">
        <div class="modal-dialog">
            <div class="modal-content">
                <div class="modal-header">
                    <h3 class="modal-title titulli1"></h3>
                    <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
                </div>
                <div class="modal-body">

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

I want to be able to edit data for role when the popup comes up and load the table after saving.