“Blocked by robots. txt” indicates that Google didn't crawl your URL because you blocked it with a Disallow directive in robots. txt. It also means that the URL wasn't indexed. Remember that it's normal to prevent Googlebot from crawling some URLs, especially as your website gets bigger.

A robots.txt file tells search engine crawlers which URLs the crawler can access on your site. This is used mainly to avoid overloading your site with requests; it is not a mechanism for keeping a web page out of Google. To keep a web page out of Google, block indexing with noindex or password-protect the page.

Retrieve the website's robots. txt by sending an HTTP request to the root of the website's domain and adding /robots. txt to the end of the URL. Parse and analyze the contents of the file to understand the website's crawling rules.

The presence of the robots. txt does not in itself present any kind of security vulnerability. However, it is often used to identify restricted or private areas of a site's contents.