I'm not sure which WebOS (if at all) version you are running, but https://www.google.com/search?q=getmein+lg+tv might work for you.

It could also be running Netcast instead of WebOS? In which case there are other ways to get in, but you'll be asking yourself "why did I do this" pretty quickly.

Join the OpenLGTV Discord and you'll have a wealth of information.