I have that exact setup. Let’s suppose you want to use layzer.lan as your domain. The way I did it:

1. Make a DNS record that maps *.layzer.lan to your IP. You can do this by either manually editing your local DNS resolver config file, or hosting a DNS server and adding a a new entry. I did the later, and chose AdGuard for that.

2. Use a reverse proxy. I use nginx-proxy-manager, and added a proxy host for each service you want to access with the link. For example, for my Immich server that is running in port 30041, I added a proxy host such that immich.layzer.lan takes you to 192.168.0.10:30041. Ports 80 and 443 have to be free for nginx to take. You can also add https support from here, and it’s very easy to do if you have bough a real domain.