I'm no expert, but my understanding is that yes, you will need to edit the atom.conf file created in the sites-available directory during installation.
Essentially, you will be updating and replacing the current section that has the config listening on port 80, and replacing it with the SSL configuration to listen on port 443. It's also considered good practice to add a redirect for any HTTP requests received on port 80 to use HTTPS instead.
I found the following third-party guide a bit easier to follow than the original NGINX link I sent you, in case it helps:
I also found an older thread in the forum with an example configuration block provided by one of our system administrators, for reference:
Hope it helps!