Cannot un-fork in github

Although you cannot “un-fork” a GitHub repository, you can do so by cloning what you’ve got into a new repository then deleting the original. This way, you’ve also removed the fork relationship.

git clone https://github.com/YOUR_USERNAME/YOUR_FORKED_REPO.git
cd YOUR_FORKED_REPO
git remote remove origin
git remote add origin https://github.com/YOUR_USERNAME/NEW_REPOSITORY_NAME.git
git push -u origin main

Now that the code is in the new repository, delete the old one from your account.