Function send 

pub async fn send(
    config: &dyn Config,
    http: &Arc<dyn HttpClient>,
    clock: &Arc<dyn Clock>,
    request: &SendRequest,
) -> SendReport

Sends one notification through the adapters this venture’s environment configures.

The adapters come from build_push — the construction serve() uses, not a second wiring — so a transport this reaches is a transport the deployment reaches, and one it reports unrouted is one every production send would answer NotConfigured for.