Where I can find the source code for Ubuntu operating system? [closed]

Ubuntu operating system is said to be open-source but I don't see its source code anywhere.

I would like to know where I can find and download the Ubuntu source code(Assembler, C, C++...).

I don't want the packages but only the Ubuntu source code.

I searched on these following websites but there are no source code files (Assembler, C, C++...):

https://cdimage.ubuntu.com/releases/22.04/release/source/

http://old-releases.ubuntu.com/releases/

http://archive.ubuntu.com/

I've found the kernel linux : https://github.com/torvalds/linux but there is not the rest.

Thks