Extract userId from trigger event

Hello,
This seems like it should be easy but I’m hitting a wall here trying to extract the userId from the event triggered from a door lock event from zwavejs2mqtt.
Here is the full event

{
    "event_type": "zwave_js_notification",
    "data": {
        "domain": "zwave_js",
        "node_id": 16,
        "home_id": 3382297610,
        "device_id": "179578cbc6f595855fbc705f310e774a",
        "command_class": 113,
        "command_class_name": "Notification",
        "label": "Access Control",
        "type": 6,
        "event": 6,
        "event_label": "Keypad unlock operation",
        "parameters": {
            "userId": 1
        }
    },
    "origin": "LOCAL",
    "time_fired": "2021-05-29T19:35:25.001029+00:00",
    "context": {
        "id": "8ef6eb046939bf28cacf3983622a3172",
        "parent_id": null,
        "user_id": null
    }
}

I can extract the parameters field with

trigger.event.data.parameters

which returns

{'userId': 1}

I thought I could use

trigger.event.data.parameters.userId

to return 1, but this returns nothing.
I’ve tried everything else I can think of at this point. Can anyone point me in the right direction?
Thank you

I was able to figure it out.

trigger.event.data.parameters["userId"]