Failed to Fetch error | Home Assistant | Page 1

I'm trying to follow this page https://developers.home-assistant.io/docs/development_environment/ and I forked the repository. However, I keep getting the "failed to fetch" issue when I copy the fork URL into the form box. What causes this error?

You'll need to set up a development environment if you want to develop a new feature or component for Home Assistant. Read on to learn how to set up.

#Failed to Fetch error