how to change default branch in github through command line code example

Example 1: change git default branch

git config --global init.defaultBranch 

Example 2: change default branch github

On GitHub, navigate to the main page of the repository.
Under your repository name, click Settings.
In the left menu, click Branches.
Under "Default branch", to the right of the default branch name, click .
Use the drop-down, then click a branch name.
Click Update.