The plugin comes with an AppImage that is used to run the [Prosody XMPP server](https://prosody.im).If this AppImage is not working, you can fallback to the Prosody that is packaged for your server. Just install the `prosody` package.
If this setting is left empty, and you are using Peertube >= 5.1 or later, the plugin will use values from your Peertube configuration file to guess on which interface and port request have to be done.
In last resort, it will use your Peertube public URI.So, any API Call will go throught your Nginx server.This could fail in some case: for example if you are in a Docker container, where the public hostname does not resolve to the correct IP.In such case, try changing the "{{% livechat_label prosody_peertube_uri_label %}}" settings, by setting `http://127.0.0.1:9000` (assuming 9000 is the port on which Peertube listen, ask your instance administrators if you don't know).
As example, this option can allow an instance of Matterbridge (once it could use anonymous login) *on the same machine* to bridge your chat with another services like a Matrix room.