How to recreate a real flight plan

    You would need to use Aerofly’s defined nice round number latitude and longitude way points for the remote areas and progress from one to another only approximating to a great circle route. SkyVector.com has/had the ability to check on your proposed flight plan allowing you to see and select a number of recently filed real world routes to check what flight plans were likely to have been perfectly acceptable to the control centres but I haven’t seen it working for a while and I think it only covered the U.S. There must be similar sim friendly facilities online.
    The route is also transiting the high artic so FMC and Area Navigation redundancy would need to be considered due to the unreliability of the magnetic compass. A navigation grid perhaps centred on the 80 degrees west meridian might be worthwhile, a major navigation discrepancy passing Russian airspace especially on the return trip would need to be avoided, there are sensitive military areas in the region and Russian airspace is totally closed to Japan, U.S.A., Canada and European countries.
    Alaskan and Canadian oceanic control would be worth researching.

    If your approximate route matches what you saw on a A350 passenger map progress then something similar in the Aerofly nav page would be great, a bigger diversion east of the Kamchatka peninsula and offshore islands would be better, the Russian airspace limits can be seen in SkyVector.
    The A350 would have an exceptionally big two engine airliner ETOPS diversion allowance but the route over northern Ellesmere Island that you show would put comfortable diversion airports more in range. A much more northerly pure great circle from Alaska to Great Britain which the Aerofly nav page might create, would in the real world require very special ETOPS approval which does exist.

    Quote from ThomK

    Can you explain in more detail what you mean by that? Thanks.

    Another flight sim has a feature that allows you to import actual routes taken from flightradar24 as a KML file.
    On the other hand, Aerofly currently requires you to manually specify waypoints, so although you can set a similar route, it's unclear whether the person actually flew that route.
    With this feature, you can recreate a route almost perfectly.