How to set alert option "subtitle"?

[Katyushka]

Hi.
Is it possible to create notification with such alert format:

"alert":
{ "body": "Body..",
"title": "Title..",
"subtitle": "Subtitle.."
}

In notification Builder there are only two methods for alert - alertBody(...) and alertTitle(...). But what about other keys for alert? Is it possible to use others alert's keys?

[JamieGHamilton]

Some of the other keys are: "action-loc-key", "loc-key", "loc-args" See Apple Docs.
In my case I needed "alert" to be a string as my existing app depends on that structure so I override the Notification class.

[krutarth-ta]

@Katyushka @JamieGHamilton were you able to figure out solution regarding how we can send extra details in alert payload?