Git push: 'fatal 'origin' does not appear to be a git repository - fatal Could not read from remote repository.'

I know similar questions have already been asked.

But, I believe my issue is due to lớn a mistake I have previously made and therefore is different: let bu explain.

Everything was working smoothly, as I could:

git add . all the files from my local repository.
git commit -m "message here" to lớn add messages to lớn my commits.
git push origin master to lớn upload my files to lớn GitHub.
git push heroku master to lớn upload my files to lớn Heroku.

However, at some point, I created a new branch locally called add-calendar-model in case next steps of the phầm mềm development would go south...

... which is exactly what happened.

However, despite many attempts, I did not manage to lớn get the initial code — i.e. the code from before I created the new branch — from the master branch to lớn my local repository.

So, I decided to lớn manually delete all the files from my local repository and git clone my master branch from GitHub.

This way, I got all my files back, but now, I cannot push any more to lớn the remote repository.

Any time I try to lớn lập cập git push origin add-calendar-model or git push origin master, I get the following error:

fatal: 'origin' does not appear to lớn be a git repository
fatal: Could not read from remote repository.

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

I am not very comfortable with Git and GitHub, as you may have guessed by now, and I have to lớn admit that I have no clue about how to lớn fix this.

Any idea?

Git push: "fatal 'origin' does not appear to be a git repository - fatal Could not read from remote repository."