Are you being asked this in an error message returned to you from Google?
If you are, the URL in that message from Google is your preview URL (the URL of your unpublished site when you preview it) A robots.txt file blocks Google from indexing parts of your site and this would prevent them from placing ads on your site. Our unpublished sites have robots.txt files attached to them. This is in order to prevent Google from indexing your site before you publish it. As soon as your site is published Google can crawl your site and place ads.
This is what happens:
1. You paste Adsense code on your site.
2. You preview your site. Your previewed page acts like a web page with Adsense code, so Google attempts to index it, but we block Google from indexing your preview URL with a robots.txt file.
That is why you get this message. Please ignore it. It does not mean that you need to do anything. It has no impact on Google's ability to index your published website and it will not interfere with Google's ability to place advertising code on your site or with your advertising revenue. Once your site is published and the ads are displaying on your site, you can safely ignore that message. Over time, as you update your content and develop your site, the Google Ads will become increasingly relevant.
If I have misunderstood you, can you let me know what it is you're trying to do and what service is asking you to access your root directory?