TV is so old that I can't even reach the site
I'm getting a connection error, from the certificate. An ssh error so I can't even connect to https://rootmy.tv, My WebOs version is 3.0, which is out of your testing interval so I'm not sure it will work even if I somehow manage to update the certificate with so little control over the browser.
If anyone knows of a way in which I can install the homebrew store or be able to install apps without the dev mode app (It's unavailable on my tv) that would be highly appreciated.
Thank you.
Your TV is indeed far too old for RootMyTV, however you might have some luck with the "getmein" exploit: https://forum.xda-developers.com/t/getmein-one-time-rooting-jailbreaking-tool-for-webos-lg-tvs.3887904/