Fix callout to localhost vs 127.0.0.1

Author: nedtwigg

selfie.dev/src/pages/py/facets.mdx

@@ -11,7 +11,7 @@ Assuming you have [installed selfie](/py/get-started#installation) and glanced t
 
 ## Our toy project
 
-We'll be using the [`example-pytest-selfie`](https://github.com/diffplug/selfie/tree/main/python/example-pytest-selfie) project from the selfie GitHub repo. You can clone the code and follow along, but there's no need to. If you did clone the project, you could run `poetry run python app.py` and you'd have a little flask webapp running at `127.0.0.1:5000`.
+We'll be using the [`example-pytest-selfie`](https://github.com/diffplug/selfie/tree/main/python/example-pytest-selfie) project from the selfie GitHub repo. You can clone the code and follow along, but there's no need to. If you did clone the project, you could run `uv run python app.py` and you'd have a little flask webapp running at `127.0.0.1:5000 ` (`localhost` might not work, make sure to use `127.0.0.1`!).
 
 It has a homepage where we can login. We can go to `/email` to see the emails the server has sent and click our login link, and boom we've got some auth cookies.