is a specific board ID. If the tool specifically says "not found," it may require manually placing the .img4 or loader files into the UnlockTool/Data/Apple/ directory on your PC. Local Service Options
Use the option within the tool for a more stable DFU exploit. Download Missing Files : loader for iphone7 2n61ap not found unlocktool patched
UnlockTool requires a specific "Loader" file to communicate with the phone’s hardware in DFU mode. is a specific board ID
This article explains the “loader not found” error for iPhone 7 (board 2N61AP) when using a patched UnlockTool, what causes it, and safe, practical steps to diagnose and resolve it. what causes it