Correct fitting of skates doesn't only involve each foot's lenght, but also width, shape/type, height/weight of the skater, how does he/she walk (gait). shape of the foot arch etc etc and this is only 100% successfully accomplished by visiting a professional figure skates fitter in person.
My feet measure 245 cm in the left foot, a little less in the right foot. My left foot is like a rabbit/cat foot, very thin and narrow, no difference of width between heel and toe box. My right foot is also thin and narrow, however the toe box is a little wider than the heel. My foot shape doesn't exactly match any of the known foot shapes (Egyptian, Greek, Roman), per analysis of my fitter however the shape they resemble most is the Egyptian shape. I wear Edeas size 255 in B width and the fitter molds my right skate to match the shape of my toe box. I can wear the left skate as it comes from the manufacturer without modifications.
Also a fitter is not only useful for fitting the shoes, but also fixing the blades to match your own alignment, and working with you to achieve the best positioning of the blades for you.
I think it would be a good idea to state which country you live at, since there are members here worldwide and maybe they know a fitter in your country that you are not aware of.
If this is absolutely impossible and you are not willing to travel to another country for fitting purposes, then there are fitters who offer virtual fittings over video calls (I go in person to my fitter, but I've heard here other members mentioning these virtual fittings to other people asking for help). Personally I don't think virtual fittings are as efficient as fittings in person, but indeed they are a much better option than trying to fit yourself with size charts and buying skates online without being fitted first.
Also, woudln't your coach be able to advice/recommend a fitter? Where do your coach/rink/club mates go to get fitted?
