This repo is intended for the linux platform, which does not have native league of legends support.
To start, make sure you are on the most recent LTS version of node/npm, have git installed and have a brain!
Next, clone the repo
git clone https://github.com/scriptkiddie-5/league-of-legends-rpc
Install the required packages with the package manager of your choice (I use pnpm)
pnpm install
If all is done correctly, run the script
node index.mjs
It checks the process list for the league client and waits for game data to be available from riot's local api, it spins up when a game is started.
Your presence will correspond to what you are doing, for example, having the client open will show this
and being in-game will show this
This script supports TFT (Teamfight Tactics) presence as well, though there is not much data available from riot's api.