Is there any way to access object id

Question

My code stopped running and this results when I tried to access room Id in the template

The error occurred django.urls.exceptions.NoReverseMatch: Reverse for 'room' with arguments '('',)' not found. 1 pattern(s) tried: ['room/(?P[^/]+)/\Z'][26/Sep/

The template where I tried to access the room id

<a href="{% url 'room' room.id %}">

The url

path('room/<str:pk>/', views.room, name="room"),


The function defined

`def room(request, pk):
    room = Room.objects.get(id=pk)
    room_messages = room.message_set.all()
    participants = room.participants.all()

    if request.method == 'POST':
        message = Message.objects.create(
            user=request.user,
            room=room,
            body=request.POST.get('body')
        )
        room.participants.add(request.user)
        return redirect('room', pk=room.id)

    context = {'room': room, 'room_messages': room_messages,
               'participants': participants}
    return render(request, 'base/room.html', context)