Installing the Proxy Base extension
The Proxy Base extension is listed among the other extension downloads on the GeoServer download page.
The installation process is similar to other GeoServer extensions:
- Visit the website download page, locate your release, and download: http://sourceforge.net/projects/geoserver/files/GeoServer/2025.1/extensions/geoserver-2025.1-proxy-base-ext-plugin.zip - Verify that the version number in the filename (for example 2025.1 above) corresponds to the version of GeoServer you are running. 
- Extract the contents of the archive into the - WEB-INF/libdirectory in GeoServer. Make sure not to create any sub-directories during the extraction process.
- Restart GeoServer. 
On successful installation, a new Proxy Base Extension entry will appear in the left menu, under “Settings”.
 
The Proxy Base Extension menu entry