Magento 2: "404 Not Found" when calling a controller

Question

I created a simple module, it is registered and shows up in
Stores -> Configuration -> Advanced -> Advanced,
then I created routes.xml and Display.php.

app\code\Jurgis\Twilio_settings\etc\frontend\routes.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
    <router id="standard">
        <route id="Jurgis" frontName="Twilio_settings">
            <module name="Jurgis_Twilio_settings" />
        </route>
    </router>
</config>

app\code\Jurgis\Twilio_settings\Controller\Index\Display.php

<?php
namespace Jurgis\Twilio_settings\Controller\Index;

class Display extends \Magento\Framework\App\Action\Action
{
  public function __construct(
\Magento\Framework\App\Action\Context $context)
  {
    return parent::__construct($context);
  }

  public function execute()
  {
    echo 'Hello World';
    exit;
  }
}

But when I go to: "http://localhost/magento2/Twilio_settings/index/display"
I get the 404 not found error.
What have I done wrong?

Answer 1

You need some little modification.

Jurgis/Twilio/registration.php

\Magento\Framework\Component\ComponentRegistrar::register(
    \Magento\Framework\Component\ComponentRegistrar::MODULE,
    'Jurgis_Twilio',
    __DIR__
);

Jurgis/Twilio/etc/module.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <module name="Jurgis_Twilio" setup_version="2.0.0">
    </module>
</config>

Jurgis/Twilio/etc/frontend/routes.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
    <router id="standard">
        <route id="Jurgis" frontName="Twilio_settings">
            <module name="Jurgis_Twilio" />
        </route>
    </router>
</config>

Jurgis/Twilio/Controller/Index/Display.php

namespace Jurgis\Twilio\Controller\Index;


class Display extends \Magento\Framework\App\Action\Action
{
    public function __construct(
        \Magento\Framework\App\Action\Context $context)
    {
        return parent::__construct($context);
    }

    public function execute()
    {
        echo 'Hello World';
        exit;
    }
}