why my app in not listed in admin panel?

I followed Writing your first Django app till tutorial 2, but my polls app is not appearing in admin panel.
In polls/admin.py, I’ve registered the Question model with the Django admin site:
from django.contrib import admin
from .models import Question
but still not showing.
I tried to check polls app using shell but app is showing in shell but why it’s not showing in admin panel. Everything is fine, still polls app not appearing admin panel.
Can anyone help me to appear polls app in admin portal? How to do that?

Do you have polls listed in your INSTALLED_APPS setting?