I have git repo living on Amazon CodeCommit but I want to save backups on Github or Bitbucket. Here's how:

Step 0 - Change Directory

First change directories to the git repo on your local drive.

cd /path/to/git/repo/

Step 1 - Add Bitbucket as a remote backup

You can create a remote git url by adding remote. In this example, I created a repo on bitbucket with an alias "mybitbucket".

git remote add mybitbucket git@bitbucket.org:chrisjmendez/repo.git

Step 2 - Add Github as a second remote backup

git remote add set-url mygithub git@github.com:chrisjmendez/repo.git

Step 3 - Business as usual

Now that you've added two remote backups, you can continue business as usual.

git add -A
git commit -m 'my commit message'
git push

Step 4 - Push to a specific repo

If you want to specifically push to your github repo.

git push -u mygithub

Step 5 - To origin an all remote backups

Push to all repos.

git push -u --all