Hey there.
I don’t think I’ve tried to get it working without SSL as far as I understand.
I will have to resarch how to do that.
I did however try starting a new VM. Last time I chose Ubuntu 18 accidently. This time I chose Ubuntu 20 (just as Ryan did). I followed the same steps (but added a CNAME as suggested) and now when I run:
anvil-app-server --app my_app --origin https://my_domain.org/ --letsencrypt-staging
Nothing happens lol. I just see the print out:
Found Anvil App Server JAR in package directory
The command line comes back to my control and no web server starts up (I think that is the right terminology).
I think this might be progress but I’m not sure 
EDIT: I can also see that despite my network security rule, the machine is not listening on port 443 when I check with sudo lsof -i -P -n | grep LISTEN .