code: def source(self):
          
          with gui.FlexForm(self.title, auto_size_text=True, default_element_size=(40, 1)) as form:
              layout = [
                  [gui.Text('Zip Backup utility', size=(30, 1), font=("Helvetica", 30), text_color='blue')],
                  [gui.Text('Create a zip backup of a file or directory.', size=(50, 1), font=("Helvetica", 18),
                            text_color='black')],
                  [gui.Text('-' * 200)],
  
                  # Source
                  [gui.Text('Select source folder', size=(20, 1), font=("Helvetica", 25), auto_size_text=False),
                   gui.InputText('', key='source', font=("Helvetica", 20)),
                   gui.FolderBrowse()],
  
                  [gui.Submit(), gui.Cancel()]]
  
              button, values = form.LayoutAndRead(layout)
              if button == 'Submit':
                  return values['source']
              else:
                  exit()
docs: Parameters for saving zip backups