opush uses autopush-rs by Mozilla as the delivery channel for push notifications on the Linux desktop and provides the DBus methods specified by the UnifiedPush specification.
The config file of opush is located at $XDG_CONFIG_HOME/opush.json (~/.config/opush.json if no other config home was specified).
The format has to be the following {"url":"wss://<URL of push-server>"} with
the URL pointing at a autopush-rs deployment.
The application state of opush will be stored at $XDG_STATE_HOME/opush.json (defaulting to ~/.local/state/opush.json).