magento2.3.5 p2 – how to override a method with plugin

Hi I’m using very nice plugin ‘login-as-customer’ by magefan.
I’d like to override an execute method of login-as-customer.
this is first time to try overriding third pirty’s controller so I stuck now.

I put files like this and expect to ignite Plugin/Login but does not.
how can i solve this?

├── Plugin
│   └── Login.php
├── etc
│   ├── di.xml
│   └── module.xml
└── registration.php


<?xml version="1.0"?>                                                                                                                                                                             
<config xmlns:xsi="" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/ObjectManager/etc/config.xsd">
   <type name="MagefanLoginAsCustomerControllerLoginIndex">
        <plugin name="intercept_login" type="MyCompanyMyModulePluginLogin" sortOrder="1"/>

namespace MyCompanyMyModulePlugin;

class Login
     * Login as customer action
     * @return MagentoFrameworkControllerResultInterface

    public function aroundExecute()
        echo "here";

finary, i want to inject an admin info into customer session. after i could solve this problem, i gonna write script in the aroundExceute.