renderfwd forwards the output image path utf-8 encoded via UDP on renders
First, download the latest release of the add-on.
Once you've downloaded the add-on, you can install it under Edit > Preferences > Add-ons > Install... by using the downloaded file.
You can configure the ip and port to which renderfwd will send the output image path under Edit > Preferences > Add-ons > renderfd.
By default the ip is set to 127.0.0.1 with the default port being 9889.