How can I noindex international folders on my website?

[jammy8891]

My client has created two international websites using the Languages function which has essentially replicated the English site on /de-de/ and /fr-fr/ however these aren't translated so I want to get these pages marked as noindex to prevent them from appearing within search engine results. I've already blocked them from crawling by customising the robots.txt file but this hasn't worked.

Is there a way in which I can noindex these entire folders?