I think this is where my lack of experience with Docker is showing.
I spun up a DO droplet and installed nginx, Docker CE, and Docker Compose. Then I went through the instructions on the page you linked to and it set it up just fine but when I went to my droplets IP address it wouldn’t connect. I had to add a config file that pointed traffic coming into the droplet on port 80 to redirect to the Docker container instead. Am I overcomplicating it?