Django doesn't reflect changes made to settings.py in production

I successfully got my Django application my server. However, I realized that I accidentally left DEBUG=True in my settings.py file. I tried setting DEBUG=False in the file, but the website won’t reflect that change. I also tried doing sudo service nginx restart but that didn’t put the change on the website. What do I need to do to get the change in effect?

As an additional note, I followed the tutorial below to get my project into production. https://www.digitalocean.com/community/tutorials/how-to-set-up-django-with-postgres-nginx-and-gunicorn-on-ubuntu-16-04