Wrong ME and wrong tools package, you system uses TXE4, start over:
Intel (Converged Security) Trusted Execution Engine: Drivers, Firmware and Tools - Special Topics / Intel Management Engine - Win-Raid Forum (level1techs.com)
EDIT1: You may try other AMIBCP versions… really dont know it can t open your dump, since you say “is an American Megatrends 5.13” usually it can open it.
EDIT2: Thats also very strange… as many FPT dumps can be open with AMIBCP, bios regions or full dumps… must be a “special” AMI bios…
Plenty of info and varies ways to mod…the forum has a search box…you can start here:
[Guide] Manual AMI UEFI BIOS Modding - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)