Hi @thiagoa, sorry this wasn’t explained in the exercise system, but we only accept fast forward pushes to a master branch. The thinking is one of both safety, and that a revision history is useful.
That said, you can just push your most recent commit, unwound to be a fast forward on current origin/master, and push that. The diff we show is always relative the base commit of the exercise, so it will ignore any other commits you made along the way.
Hope that helps, and sorry again for the lack of clarity.