This is a static HTML file and can be used locally.
If you use it from a shared domain (e.g. rawgit.com), other scripts on that domain may have access to data you enter here, including your embed secret :(
You can use the domain fabio-looker.github.io instead.
This is for demo/understanding only. You should never make your embed secret available to a user's browser!
Check the [Properties] button for additional parameters you can configure
If you want to use the Embed URI Validator in Looker, embedding here will consume the nonce and cause the URL to be invalid. Uncheck the "Preview" checkbox at the bottom to not embed after building the URL.