I downloaded ROM - CAN-L11C432B392 from this site: http://www.stechguide.com/huawei-nova-b392-nougat-update/. Then I created dload folder on SD and extracted update.app there. And nothing. On 53% phone showed error.
In Poland we have polish brand 3mk that makes protective film on whole screen - https://folie-ochronne.3mk.pl/pl/p/Huawei-Nova-Folia-na-caly-ekran-3mk-ARC/37015. I have this and it's very good and looks very well.