QGBinaryFile is an option for QGCreateAmp,
which specifies the full path to the QGRAF binary. When set to
Automatic, the default binary is"qgraf" on
Linux and macOS or "qgraf.exe" on Windows, which resides in
FileNameJoin[{$FeynHelpersDirectory, "ExternalTools", "QGRAF", "Binary"}].
If you provide a different location, you must ensure that the
containing directory is user-writable, since QGCreateAmp
will need to save an automatically generated "qgraf.dat" in
that directory and delete it afterwards.