code: def register_plugin(self):
          
          self.breakpoints.edit_goto.connect(self.main.editor.load)
          #self.redirect_stdio.connect(self.main.redirect_internalshell_stdio)
          self.breakpoints.clear_all_breakpoints.connect(
                                          self.main.editor.clear_all_breakpoints)
          self.breakpoints.clear_breakpoint.connect(
              self.main.editor.clear_breakpoint)
          self.main.editor.breakpoints_saved.connect(self.breakpoints.set_data)
          self.breakpoints.set_or_edit_conditional_breakpoint.connect(
                             self.main.editor.set_or_edit_conditional_breakpoint)
          
          self.main.add_dockwidget(self)
          
          list_action = create_action(self, _("List breakpoints"),
                                     triggered=self.show)
          list_action.setEnabled(True)
          pos = self.main.debug_menu_actions.index('list_breakpoints')
          self.main.debug_menu_actions.insert(pos, list_action)
          self.main.editor.pythonfile_dependent_actions += [list_action]
docs: Register plugin in Spyder's main window