How to limit MacBook Pro charging to 80%?

Hi All, I'm on a MacBook Pro with MacOS Big Sur 11.7.10. I've searched the internet on how to limit the battery charging to 80% and all of them point to "Optimize charging" feature of the OS. The problem is I don't have that option. Most of the instruction start with "System Settings" which I don't have. The closest thing on my MacBook is "System Preferences". Hence, everything after that in the instruction doesn't make sense to me.