Gunicorn fails to start - 'Job for gunicorn.socket failed'

I’m on Ubuntu 19.04 - is this the problem?

I’ve followed this tutorial:

https://www.digitalocean.com/community/tutorials/how-to-set-up-django-with-postgres-nginx-and-gunicorn-on-ubuntu-18-04

And once I get to the part about starting Gunicorn, I’ve added the commands to gunicorn.socket and gunicorn.service, but following the ‘sudo systemctl start gunicorn.socket’ command, I get an error - 'Job for gunicorn.socket failed.

It asks me to check the status of the socket for details:

 gunicorn.socket - gunicorn socket
   Loaded: loaded (/etc/systemd/system/gunicorn.socket; enabled; vendor preset: enabled)
   Active: inactive (dead)
   Listen: /run/gunicorn.sock (Stream)

gunicorn.service

[Unit]
Description=gunicorn daemon
Requires=gunicorn.socket
After=network.target

[Service]
User=phillyharper
Group=www-data
WorkingDirectory=/home/phillyharper/versal
ExecStart=/home/phillyharper/versal/versalenv/bin/gunicorn \
          --access-logfile - \
          --workers 3 \
          --bind unix:/run/gunicorn.sock \
          versal.wsgi:application

[Install]
WantedBy=multi-user.target

gunicorn.socket

[Unit]
Description=gunicorn socket

[Socket]
ListenStream=/run/gunicorn.sock

[Install]
WantedBy=sockets.target