comment changer le mode base du terminal

If you are referring to changing the default command shell per the Related Article linked above, that describes how to switch the default command shell for your macOS login sessions.

If you are referring to the "(base)" string shown in the prompt string in the image included, that is whatever is used in your PS1 prompt string in your particular login, and—if your prompt includes your hostname—then that string is what your local network is returning as the hostname for your computer.

An example of a PS1 prompt string:

user@host-1001 ~ % echo $PS1
%n@%m %1~ %# 
user@host-1001 ~ % 

A tool to help generate PS1 strings: https://bash-prompt-generator.org/

The details of the prompt string implementation and syntax can vary by the selected command shell.

If you're asking about something else, please include a few more words and a little more background.