Zip archive filed under Xiaomi and catalogued as BIOS firmware for main board NB2766, with PCB MB version V4 stated in the name. The 17.1 MB size suggests it may hold more than one image or supporting files, so extract it and inspect the contents before use. Compare the NB2766 marking and V4 revision on the laptop board with the archive, read and back up the existing SPI flash with a programmer, and check that the image size equals the chip capacity before writing anything.
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 .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →