APM tags/labels not showing up in Kibana

I would like to send some labels along with the stacktrace to the Elastic APM server from the client side. Using the @elastic/apm-rum javascript agent, I'm calling apm.addLabels({ ... }) and passing my object. Looking at the request in my browser, the labels look like they are being sent properly. Here's the relevant part of the request.

{
    "metadata": { ... }
}
{
    "error": {
        ...
        "context": {
            "page": { ... },
            "labels": {
                "browser": "chrome",
                "os": "Windows 10"
            }
        }
    }
}

I am expecting that the browser and os labels show under the Labels tab in the error report, but instead I'm seeing this.

So my question as an elk novice is, what additional configuration do I need to get the labels in the report?