TTX 3.0 -- From OpenType To XML And Back

[Adrian]

On Mac OS X, in Terminal I'm using Python3 (3.7) with a 'ttx' module from Adobe Font Development Kit

The 'ttx' module merges a Digital Signature table (dsig) into a TrueType (ttf) font by exporting to xml and back again to ttf file.

Adrians-iMac-2:~ adrianshome$ which ttx
/usr/local/bin/ttx
Adrians-iMac-2:~ adrianshome$ /Users/adrianshome/bin/FDK/Tools/osx/ttx -m /Users/adrianshome/Desktop/Dsig\ fldr/SassoInfProReg.ttf 
usage: ttx [options] inputfile1 [... inputfileN]

Error:
ERROR: Must specify at least one input file
Adrians-iMac-2:~ adrianshome$ 

I have received various error messages and this latest error is the first that makes sense.  Have I put the input file in the wrong order in the code? or is there some other reason for the error?

These instructions worked for me in the past with previous versions of Python and Adobe's ttx module.

Still confused,
Adrian