(I'm not sure if the English-language text is exactly that, I translated from Russian).However, even in Microsoft File Explorer there is a "Rename file" option: "Do you want to rename %filename% to %filename — copy (#)"? A file with the same name already exists in this location.
In the FAR file manager, a similar feature is described as
Existing file will not be changed, a new name will be given to the file being copied.
In PDF-Tools, this is calledExisting target files will stay unchanged, copied files will be renamed.
When file already exists: Save new with other unique name (autonumber).