how to add updated code to github project throught git code example

Example 1: git push existing repo

cd existing_folder
git init
git remote add origin https://gitlab.com/abc.git
git add .
git commit -m "Initial commit"
git push -u origin master

Example 2: how to add an existing project to github

# Go into your existing directory and run below commands
cd docker-spring-boot
echo "# docker-spring-boot" >> README.md
git init
git add -A
git commit -m "first commit"
git branch -M master
git remote add origin https://github.com/devopsmaster/docker-spring-boot.git
git push -u origin master