This happens because you're using SSH url and probably your SSH settings are not configured (you're also saying your ~/.ssh
directory is empty).
You can check the current remote url(s) using the following command:
git remote -v
If you want to use basic authentication (username + password), you have to use https.
Do this in your repository:
git remote set-url origin https://github.com/your-username/repository.git
Replace your-username
with your GitHub username and repository
with the repository name. Also, replace origin
with your remote name (if you're using another remote name, probably you are not).
As @Abizern mentioned, you can configure the SSH keys and use the SSH urls instead. That may speed up your work not annoying you to enter the username/password every time.
There are other alternatives to prevent git from asking for your password every time. Here is one of them, by setting the cache time.
...or you can provide your password/token in the HTTPs url, as mentioned here.
git remote set-url origin https://username:password@github.com/username/repository.git