code: def register_plugin(self):
          
          self.redirect_stdio.connect(self.main.redirect_internalshell_stdio)
          self.main.console.shell.refresh.connect(self.refresh_plugin)
          iconsize = 24 
          self.toolbar.setIconSize(QSize(iconsize, iconsize))
          self.main.addToolBar(self.toolbar)
docs: Register plugin in Spyder's main window