How do I push an existing repository?

So I’m following the command line instructions

Push an existing Git repository

cd existing_repo git remote rename origin old-origin
git remote add origin ist-git@git.uwaterloo.ca:h34sun/even-cycle-transversal.git
git push -u origin --all git push -u origin --tags

It’s asking me for ist-git@git.uwaterloo.ca’s password: I’m not sure what to do here my github pass does not work are only administrators able to push repositories?