I am integrating a third-party site with Salesforce LiveAgent to include passing in an external ID for a Contact record.
Following the instructions at this site I have a simple web page set up (omitting irrelevant portions, IDs and URLs sanitized):
This works: it brings up a chat window and it connects correctly. However, I need to pass the
externalId variable into LiveAgent somewhere: this functionality is not covered by any documentation or tutorial that I can find.