BIOS archive for an X450LD at revision 2.1, almost certainly the ASUS model, though the brand is not stated in the name, packed as a 3.23 MB RAR. Match the revision printed on the PCB before flashing. Extract the image and confirm its size equals the SPI chip capacity. Read and keep the existing chip contents with a programmer first, so the board can be restored if the image does not suit it or causes problems.
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 @biosarchive. 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.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →