An archive of repair files for Lenovo hardware. Shared as “IdeaPad 5 2-in-1 14IRU9 83DT nb6837c.rar” — a .rar file, 24.4 MB.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @boardsscanrepo. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
7-ZipWinRARThe Unarchiver (macOS)