Missing required parameter for Route

Not sure how to fix this error!

Route

Route::prefix('registrar')->name('registrar.')->group(function() {
    Route::resource('/users', UsersController::class, ['except' => ['create', 'store', 'show']]);
});

Link to edit page

      <a href="{{ route('registrar.users.edit',$user) }}"><button type="button" class="btn btn-sm btn-primary">Edit</button></a>

Controller

 public function edit(User $user)
    {
        $roles = Role::all();
        $user = User::find($user);
        return view('registrar.users.edit',compact('user','roles'));
    }

Edit Page Form Route

 <form action="{{ route('registrar.users.update',$user) }}" method="POST">
                @csrf 
                @method('PUT')
                @foreach($roles as $role)
                       <div class="form-check">
                       <input type="checkbox" name="roles[]" value="{{$role->id}}">
                       <label>{{ $role->name}}</label>
                       </div> 


                @endforeach
                
                </form>