Gotify Notifications with Image using Node Red

[final quiver]

I am trying to include an image when sending a notifcation to Gotify in Node Red. I have referenced the documentation here: https://gotify.net/docs/msgextras

I get the message in Gotify, but just the title, message text and alert sound. Nothing appears for the image. Anyone get this working?

Here is the function code that I am using:

msg.payload = {
"message": "my message",
"title": "my title",
"priority": 5,
"extras": {
"client::notification": {
"click": { "url": "https://gotify.net" },
"bigImageUrl": "https://avatars.githubusercontent.com/u/36410427?s=200&v=4"
},

    "android::action": {
        "onReceive": { "intentUrl": "https://gotify.net" }
    }
}

};

return msg;

[echo vault]

You've tried expanding the notification, and that doesn't reveal the image?