Automatically add a private note to chat incidents

Content

Hi everyone,

I'm working on having a private note added to the incident thread automatically after the chat has been wrapped-up. Although this may not seem like much, we are trying to reduce the amount of manual work for our agents where possible.
(A bit more background: Our chat agents add a private note at the end of every chat to provide a short description about the inquiry.)

I've reviewed the available options in the incident workspace rules and found the then action 'Add standard text to thread'. The problem I'm having is finding a suitable trigger that I can use to fire this action.