git [rejected] master -> master (non-fast-forward) code example

Example 1: [rejected] main -> main (non-fast-forward)

git pull --rebase         this will solve the issue

Example 2: rejected master -> master (non-fast-forward)

git push -f origin master !!This is never a recommended use of git. This will overwrite changes on the remote. Only do this if you know 100% that your local changes should be pushed to the remote master.