Upgrade Debian on Raspbian

[Claudio Vicario]

Hi everyone,
i have a Raspberry Pi 3 with Raspbian Lite (based on Deb11) and i need to 
upgrade to Raspbian Lite (based on Deb12), or the last version of Raspbian 
comparable with my Raspberry Pi 3 Model B+.
Which cmd i need to use in kernel?
Claudio Vicario