After going through every bit of the Internet, I noticed that setting up multiple monitors on Optimus laptop running Kali linux is not an easy job. Even Kali linux official documentation does not have it for a laptop. They only have it for desktop users, which is a totally different use case. Spent days to work through and finally got it working.

So I just wanted to share all the details on how to get it working. Here's the link to the post: https://9oelm.github.io/2021-09-17--set-up-multiple-monitors-on-optimus-laptop-running-kali-linux/

Good luck and happy hacking!