I have a web application that sends Websockets. When I fire up Thunderbird it connects to that specific websocket server.

I'm try to open a new Compose Mail window when I receive a perticular type of message (from that websocket)

However, I'm getting this error : Uncaught (in promise) Error: composeAction.openPopup may only be called from a user input handler

Is there any way around this? Or do I absolutly need some kind of in app use input for this method to work ?

Basically, on my web app, I have a button that should open a new mail with a PDF attached and some prefilled content(Which mean, I can't just use mailto:)

The current code is:

ws.addEventListener('message', function (event) {
    browser.composeAction.openPopup()
});

Thanks