修改评论后无法再次提交提交

Question

$ git commit -m "original comment"    
$ git push origin B02913

然后我更改了提交的注释，但未能推送到企业Gibhub网站：

$ git commit --amend -m "modified comment"                                                    
$ git push origin B02913                                                                            
  To https://xxx
 ! [rejected]        B02913 -> B02913 (non-fast-forward)
error: failed to push some refs to 'https://xxx'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

为什么第二次推送不能在GitHub上重写提交的注释？

我现在该怎么办？

感谢。