ImageBoards.net is a frontend for github.com/imageboardsnet/imageboards.json you need to make a pull Request there.
git clone command with your fork's URL to clone it to
your local machine.
git clone https://github.com/your-username/imageboards.json.git
git checkout -b your-branch-name
git add .
git commit -m 'A descriptive message about your changes'
git push origin your-branch-name