Cannot get past this apparently simple problem !

Tried -

Home/Desktop/cnctest

~/john/Desktop/cnctest/

and many other combinations !

Any ideas please ?

EDIT I'm using version 1.3.2 in Ubuntu 22.04

EDIT2 changed uppercase H to lowercase h for 'home'directory, but it produces a new problem !

(100.0; 0.0; -1.00000)
(0.0; 0.0; 0.00000)
Cutting tool has not been defined! A default tool has been automatically added.

(100.0; 0.0; -1.00000)
(0.0; 0.0; 0.00000)
(100.0; 0.0; -1.00000)
(0.0; 0.0; 0.00000)
Traceback (most recent call last):
  File "/snap/inkscape/10555/share/inkscape/extensions/other/gcodetools/gcodetools.py", line 5930, in <module>
    Gcodetools().run()
  File "/snap/inkscape/10555/share/inkscape/extensions/inkex/base.py", line 250, in run
    self.save_raw(self.effect())
  File "/snap/inkscape/10555/share/inkscape/extensions/other/gcodetools/gcodetools.py", line 5881, in effect
    self.options.active_tab()
  File "/snap/inkscape/10555/share/inkscape/extensions/other/gcodetools/gcodetools.py", line 3873, in tab_path_to_gcode
    self.check_dir()
  File "/snap/inkscape/10555/share/inkscape/extensions/other/gcodetools/gcodetools.py", line 3262, in check_dir
    dir_list = os.listdir(self.options.directory)
PermissionError: [Errno 13] Permission denied: '/home/john/Desktop/'

The last line seems to be the  important one.