So, have you ever had a situation where you accidentally pushed the wrong tag to your remote repository and need to undo this?
You can first delete the tag on your local copy.
git tag -d TAGNAME
Then push the tag to the remote repository.
git push origin :refs/tags/TAGNAME
Create the tag again on your local copy
git tag -a TAGNAME -m 'same tag name, new commit'
Then push the new tag to your remote repository.
git push origin TAGNAME
Further Reading https://git-scm.com/docs/git-tag