I also believe it’s possible to set up HTTPS encryption without a domain name, but it might result in that “we can’t verify the authenticity of this website” warning in web browsers due to using a self-signed certificate.
Just create your own rootCA and IntermediateCA and sign your certificate with those, put the CA in your trust store of your system and get rid of this self-signed warning on every device and happily access all your service via: *.home.lab or whater ever local domain pleases you.
Fair point ! Yeah sure if you host a blog online it doesn’t make sense… But if you only self-host your services for family and some friends and access them over VPN, a local CA is actually a privacy respecting choice.
Hosting something on the web (specially self-hosted) without the propre software and hardware is a bad idea in the first place anyway !