You need to have Node installed, as well as npm which comes bundled with node. Commands:

git clone https://github.com/Cosmin-Mare/y-codemirror-react.git

cd y-codemirror-react

npm i -> if this gives error, then npm i --legacy-peer-deps

npm start to run app.

if that gives an error, ctrl+C to stop the app and then:

1. for windows: run $env:NODE_OPTIONS = "--openssl-legacy-provider" from Powershell.
2. for Linux, MacOS, bash: export NODE_OPTIONS=--openssl-legacy-provider

And then try npm start again