Could not read from remote repository

Got this error when pushing code to GitHub:

Developers-iMac:experiment-react-route-based-lazy-load dev$ git push -u origin master
Warning: Permanently added the RSA host key for IP address '13.250.177.223' to the list of known hosts.
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

One solution that works:

Developers-iMac:experiment-react-route-based-lazy-load dev$ git remote set-url origin https://github.com/ienablemuch/experiment-react-route-based-lazy-load
Developers-iMac:experiment-react-route-based-lazy-load dev$ git push -u origin masterEnumerating objects: 28, done.
Counting objects: 100% (28/28), done.
Delta compression using up to 8 threads
Compressing objects: 100% (28/28), done.
Writing objects: 100% (28/28), 302.35 KiB | 12.09 MiB/s, done.
Total 28 (delta 2), reused 0 (delta 0)
remote: Resolving deltas: 100% (2/2), done.
To https://github.com/ienablemuch/experiment-react-route-based-lazy-load
 * [new branch]      master -> master
Branch 'master' set up to track remote branch 'master' from 'origin'.

Got the solution from: https://stackoverflow.com/questions/21255438/permission-denied-publickey-fatal-could-not-read-from-remote-repository-whil/55239661#55239661