CI4 Modules Code not work

One issue might be this line

PHP Code:

public $psr4 = ['Modules' => ROOTPATH.'modules']; 


You indicate that the modules directory is at /application/modules so the above should probably be

PHP Code:

public $psr4 = ['Modules' => APPPATH.'modules']; 


You don't show the namespace of class Node. It will need to be properly defined if it's not already.