I finally accessed via FTP. I edited the file I was working with, and voilà.
Once the problem with the code was solved, and without further modifications, the problem with the login at WordPress disappeared, and it now can recognize my password.
Thanks again.
I mark the topic as resolved.
Thanks for your swift response.
I have a backup of the code in a .txt file, I can use it ti reupload. The problem is that, since the error happened, I can’t log in to WordPress: I write my user and password, and then I keep getting the error “invalid username”.
