The bottom of the article mentions:

"To see plugins in action, try this multi-agent workflow we use to develop Claude Code

`/plugin marketplace add anthropics/claude-code`"

So I tried it out and got myself into:

"Failed to clone marketplace repository: SSH authentication failed. Please ensure your SSH keys are configured for GitHub, or use an HTTPS URL instead.

Original error: Cloning into '/Users/brutalcoding/.claude/plugins/marketplaces/anthropics-claude-code'...

fatal: Could not read from remote repository.

Please make sure you have the correct access rights and the repository exists."

Fixed it by running this instead: "/plugin marketplace add https://github.com/anthropics/claude-code".

It makes sense to me, but I just wanted to point it out :-)