How do I configure my WiFi router settings?
How can I change my WiFi security settings?
MacBook
We'll assume that you have an Apple router, correct?
On your Mac, open Finder > Applications > Utilities > AirPort Utility
Click on the AirPort router
Click Edit
Click the Wireless tab at the top of the next window
The security settings are here
What settings are you trying to change?
The Apple AirPort router is already set up for the highest security of which it is capable. You can lower that setting, but it is not recommended.
If you are asking about newer types of security like WPA3, or 802.11ax or WiFi 6, the Apple routers do not have this capability.
Remember, even the most recent Apple router was designed in 2013 using technology that was available at the time. Advances in security was still years away when the AirPorts were designed.