Mirroring a repository

1．Open Git Bash.

2．Create a bare clone of the repository.

$ git clone --bare https://github.com/exampleuser/old-repository.git

3．Mirror-push to the new repository.

$ cd old-repository.git
$ git push --mirror https://github.com/exampleuser/new-repository.git

4．Remove the temporary local repository you created in step 1.

$ cd ..
$ rm -rf old-repository.git

Reference and Credit: https://help.github.com/en/articles/duplicating-a-repository