View does not render Template

I create IndexView and extends AppView, the method render is called, but my template don’t render, i try

public function render($view = null, $layout = null) {
	$this->layout = 'index';
    echo 'hello'; // It works but the page is blank

In my controller I call

What version of CakePHP? What do you want to achive? Why do you need the dedicated render method?

Version 3.4.
How does the view work? Isn’t it between controller and template?
I want to treat injections in template of CSS and JS, footers and headers.

Correct me if I’m wrong

My template

<!DOCTYPE html>
<html lang="pt-br">
    <link href="/favicon.ico" type="image/x-icon" rel="shortcut icon"/>
    echo $this->Html->charset('UTF-8');
    echo $this->Html->meta('description', 'Description');
    echo $this->Html->meta('viewport', 'width=device-width, initial-scale=1');
    echo $this->fetch('meta');
    echo $this->fetch('css');    
<body id="home">
    echo $this->Html->script(['facebook.min.js','google.min.js']);
    // code html here ...
    echo $this->fetch('header');  // inject header
    // code html here ...
    echo $this->fetch('content'); // inject body
    // code html here ...
    echo $this->fetch('footer');
    echo $this->fetch('script'); 

Your example is a layout, located at /src/Template/Layout

$this->fetch('content'); will display for example /src/Template/Posts/index.ctp

In /src/Template/Posts/index.ctp you can add additional css and js files like this
echo $this->Html->script('your_extra_js.js', ['block' => true]);

Is this what you need?