Dialogflow UX: How to access the user.utterance

[MarcGyarmaty]

Hi everybody,

i would like to send the last User utterance to a Webhook, but there doesn´t seem to be a placeholder for this.
"$last-user-utterance" only works inside a Generator, but nowhere else.
Bard suggested "$session.params.user_message", which does not work.

How can i access that last User message? I would like to send it to a RAG pipeline for answering of "open question answering"

thanks