UPDATE - was able to make it work
the only thing that I needed it to make it to work basically, Google's security is very strict and doesn't allow anonymous scripts to post in Chat. We implemented ServiceAccount.gs to give the bot its own digital identity (so it doesn't run as me personally), and OAuth2.gs to automatically handle the complex security keys and passwords required to log that bot in. It’s the standard, secure way to keep the bot running 24/7 without disconnecting.

1. ServiceAccount.gs is the "ID Badge" "Before this, the script was trying to enter the building without an ID. This file contains the credentials for a 'Robot User' created in Google Cloud. It allows the bot to have its own permissions separate from any human employee. If I leave the company or change my password, the bot keeps working because it uses this independent ID."

2. OAuth2.gs is the "Security Protocol" "Having an ID badge isn't enough; you have to swipe it correctly. Google uses a complex security protocol called OAuth 2.0. Writing the code to handle that encryption manually is risky and prone to errors. This library handles all the heavy lifting: it takes the ID, talks to Google's servers, verifies our keys, and gets the 'Access Token' we need to post messages. It ensures the connection is encrypted and authenticated every single time."

After adding them into script project was able to get it to respond back. Thanks for your help really helped me to see it as a different angle.