On a Plesk server with Nginx enabled here are the steps to setup custom X-Robot-Tag headers has described here:
https://developers.google.com/webmasters/control-crawl-index/docs/robots_meta_tag?csw=1
In Plesk control panel:
1. Select the domain
2. Click Web Server Settings
3. Scroll down to nginx settings
4. If you have “Serve static files directly by nginx” checked (which I recommend), you’ll need to remove the file extensions to which you’re going to apply headers. In this example remove “pdf” from the list.
5. In the “Additional nginx directives” field enter:
1 2 3 |
location ~* \.pdf$ { add_header X-Robots-Tag "index, noarchive, nosnippet"; } |
6. Click OK button to save changes.