Discussion on: How to implement the functionality to host any web app on a given domain through a single command similar to the discourse?

[Si]

I think you need to take a step back. It's great to have an end-goal but I think you're trying to run before you've learnt to walk.

• Have you bought a domain? If not, that's step one.
• Then go get a server from a cloud provider (Digital Ocean, AWS, GCP etc)
• Install Nginx and make a Hello world App on that server that serves content through a REST API
• Access the app using the servers public IP/port etc
• Learn to set-up your domain name using an Nginx reverse proxy
• Learn to set-up a subdomain

There are some very generic steps, because I don't know your skill level.