The Debian package of the alertmanager does not include a web application.
Please, use the amtool command-line application to obtain
equivalent functionality.
Alternatively, you can build and deploy the UI yourself, by placing
the generated files in
/usr/share/prometheus/alertmanager/ui/, or by using the
--web.ui-path option to point to a different path.
The script located at
/usr/share/prometheus/alertmanager/generate-ui.sh can
automatically build and deply the UI.
You can still use the HTTP API, and the special handlers: