How to upload data to GITHUB after commit changes (amend)?

Question

git

created a post branch locally in the project, made changes9 and uploaded it to the server, then made more changes9 and made a commit, made some more and decided to add files to the same commit, entered the command
git add --all
git commit --amend -m "category in post"
and decided to upload to the server
git push origin post
gives an error
! [rejected] post -> post (non-fast-forward)
error: failed to push some refs to 'git'
tooltip: Updates were rejected because the top of your current branch
is behind its outer part. Check in and merge the external
tooltip changes (for example, using "git pull ...") before trying to push the
tooltip changes again.
hint: For more information, see "Note about fast-forwards"
Tell me what 9 did wrong and how can I upload it to the host now?

Answer 1

hint: Updates were rejected because the top of your current branch
hint: behind the outside of it. Check in and merge the external
tooltip changes (for example, using "git pull ...") before trying to push the
tooltip changes again.
Hint: See "Note about fast-forwards" for more information.

Answer 2

git push origin +post