Below are the easy steps: -
On GitHub, navigate to the main page of the repository.
Under your repository name, click Upload files.
Drag and drop the file or folder you'd like to upload to your repository onto the file tree.
At the bottom of the page, type a short, meaningful commit message that describes the change you made to the file. You can attribute the commit to more than one author in the commit message.
Below the commit message fields, decide whether to add your commit to the current branch or to a new branch. If your current branch is master, you should choose to create a new branch for your commit and then create a pull request.
Click Commit changes.