app_uninstalled slack event does not return the entire json as shown in the documentation

Clash Royale CLAN TAG#URR8PPPapp_uninstalled slack event does not return the entire json as shown in the documentation
As the title says, the slack documentation in the link below
https://api.slack.com/events/app_uninstalled
does not return the entire json, I am using @slack/events-api package
and my code is something like this
slackEvents.on("app_uninstalled", handler)
the handler function only received the event part of the entire json
{
type: "app_uninstalled"
}
why is this happening?
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