Hopefully we can resolve that!
I tried going the reverse proxy route but that doesn’t help because I don’t own a domain name so certbot won’t send me any certs.
Now I'm confused: The error you presented comes from Nginx. The only role that Nginx has in the installation instructions *is* as a reverse proxy (but you're no longer trying to go that route?). From where I stand, those are contradictory signals. Can you provide a bit more information of what you *have* done, which information you used to do it (including a link to the installation instructions you're using) and which steps you considered successful, if any?
Which was unexpected, I just wanted to run this software on my own home network but that presents a problem
as I am at a complete loss how to install the software and configure it in such a way that I can simply access it on my private home network.
Ok. I think you may have missed the key point of Pete's mail: you are almost there and if you're the only user, there's no need to have the reverse proxy, but you *do* need the server to listen on an address which can be reached from the other devices on your home network. It's the "reachable from the other devices on your home network" part which you had not achieved yet in the mail he answered to, because the server was strictly listening to connections from itself.
Is there any guide or lesser known website that lays out what is required to simply self host the software on a private network without the necessity of having a domain name?
I'm not aware of any lesser known sites which document it. There's explicitly not a guide on the main site because it might encourage people to set up LedgerSMB insecurely. However, in your use-case, getting a certificate is indeed overkill (although you could generate a so called self-signed certificate, which would eliminate the need of owning a domain to go to certbot, but that's a whole can of worms in itself). So, when I know what is your reference documentation and to what step you have completed the instructions, I can probably indicate what you need to do to bind the serverprogram to an external address instead of an internal address. That way it will become reachable from other network devices.
Regards,