"Found inside the Last Book Vol.1. Is there a special way to use it?"
The Medal of Eagle, or Eagle Medal, is an item in Resident Evil.
The player must place it in the hollow slot on the east side of the Courtyard Fountain. Placing both medals will open the entrance to the lab.
The medal is found inside the Last Book Vol. 1, located inside the Courtyard Study. Examining the side of the book will open it, revealing the medal.