Error: Command failed: git push --force heroku `git subtree split --prefix=frontend main`:refs/heads/main fatal: 'main' does not refer to a commit remote: remote: ! Push rejected, cannot delete main branch remote: To https://git.heroku.com/***.git ! [remote rejected] main (pre-receive hook declined) error: failed to push some refs to 'https://git.heroku.com/***.git'