YMMV, but regarding history writing, asking for help finding sources is normal, and there is nothing unethical in asking for help finding information.

It would be unethical to use material written by someone else or have someone produce a literature review for you (assuming they are not your co-author). However, asking for direction on reading that you plan to do and will evaluate and utilize as you see fit should be completely fine.

If you are concerned about the ethics of soliciting help finding literature, then I would ask your advisor, committee, or lead investigator (whichever you may have for your particular MSc). While in history, this is normal (if not expected), I am not entirely sure how other fields (or individual faculty within them) view it.

If you check out a history monograph, you will often find in the acknowledgments where authors acknowledge the help they received from other historians, librarians, archivists, etc., who might know the contours of particular literature or series of documents and who give advice on how best to tackle it. For instance, if I suddenly switched gears and started researching or writing on a new area, era, or methodology, I would reach out to people I know who already have the expertise and get advice on navigating it.