-
Create or find a gist that you own.
-
Clone your gist (replace
<hash>with your gist's hash):# with ssh git clone [email protected]:<hash>.git mygist # with https git clone https://gist.github.com/<hash>.git mygist
-
Change to your gist’s directory:
cd mygist -
Add and commit the image:
git add tulip.jpg git commit -m "Add tulip to gist" -
Update remote:
git push origin master
See blog post.

@xurizaemon @angusgrant
FWIW, for me, github was always working fine, but I had a similar error message when I did my first
push. Because I have TFA with my login, I had to use my username and token (not password). Once I did that one time, my ssh key was correctly used subsequent times.https://help.github.com/en/articles/creating-a-personal-access-token-for-the-command-line