To call a wizard remotely you need to:

-> For testing on core:
    export URE_BOOTSTRAP="file:///home/'USER'/git/libo/install/program/fundamentalrc"
    export PYTHONPATH=/home/'USER'/git/libo/install/program
    #and run LibreOffice in listening mode:
    ./soffice --"accept=socket,host=localhost,port=2002;urp;"
      
-> For testing on installed LibreOffice:
    export URE_BOOTSTRAP="file:///usr/lib/libreoffice/program/fundamentalrc"
    export PYTHONPATH=/usr/lib/libreoffice/basis-link/program
    #and run LibreOffice in listening mode:
    soffice --"accept=socket,host=localhost,port=2002;urp;"
      
-> Launch the wizard from wizards parent folder:
    python
    #Fax wizard
    from wizards.fax.FaxWizardDialogImpl import FaxWizardDialogImpl
    FaxWizardDialogImpl.main()
