How can I fix iframe embedding when facing a Content Security Policy error?

Just to clarify, if you're looking to embed that website publicly, it won't work unless they allow it. Disabling Content Security Policy in your browser is only a workaround for local development. And no, in a production environment, Content Security Policy is usually enforced, so you'd need to find another solution or stick with sites that allow embedding.

It looks like you're trying to embed an external website in your iframe. The error you're seeing means that the site you're trying to frame doesn't allow itself to be embedded in iframes on other sites due to its Content Security Policy. If you're just testing it locally, you could potentially disable Content Security Policy in your browser for testing purposes, but that's not a real solution. For a public website, keep in mind that you'll need cooperation from the site you're trying to embed if you want it to work without changing security settings.