Code expressions assistance inside Action | Group Chat Bubbles implementation

Hi everyone,

I am using the chat group bubble for my flutterflow app. I have a grid of user profile, when I click on any of them I have a "send message" button to be able to individually chat with that individual user.

I am adding two actions: Cloud Function to "CreateOrGetChat" and a Navigate action to navigate to the chat_2_details page. I am passing a parameter "chatRef" to the navigation button but having a hard time adding a value to it.

My first thought is to add a code expression functions.httpsCallable('createOrGetChat')(context.auth.uid, data.recipientUserId). But looks like code expressions are not displayed in the available options.

Any alternative idea to that? Much appreciated!
It would be extremely helpful if someone has some documentation or tutorial on chat group bubbles flow.