Genesys Web Messaging SDK: Passing CRM ID in startChat()

NICE CXone API & Integrations
1

Can someone show me the exact syntax for passing a CRM customer ID when calling startChat() in the Genesys Web Messaging SDK?

I’m trying to set it up so the ID flows through to the agent, but I keep getting a 400 Bad Request when I include the attributes object.

Here is what I have so far:

widget.startChat({
 attributes: {
 crmId: '12345'
 }
});

Is this the right structure or am I missing a specific key?