React extension error

I’m working on a React Twitch extension.
An error occurred while setting up HTTPS by viewing the Twitch extension Docs.

When run this command

yarn postinstall

It causes problem

Created a new certificate valid for the following names �
 - "localhost"

The certificate is at "cert.pem" and the key at "key.pem" ✅

It will expire on 19 July 2024 � line 6: node_modules/webpack-dev-server/ssl/server.pem: No such file or directory
Done in 2.82s.

Somebody help?

This example is pretty old

And wise to skip it.

The step you are tripping up on pertains to Self Signed cert generation.
Which you might or might not need depending on how you setup your Development Environment.

So this is a dev env issue. so set up the dev env not like this example is configured.