How to dispaly [1-2] rather than [1,2] in consecutive citation?

without waiting for the modification of the program, which will probably take some time, you could make these “hidden text” and type in the format you want them to appear in.  formating them as hidden text means you can still “see them” in the word processing document, but they won’t print, so if the numbering changed, you could see it and manually correct your version.  Search for “hidden text” before submitting the final version, to check they all match.