I have to embed a contact form inside of a block, and im trying to use the entity.form_builder service, But im not sure which entity i should give it, i found Message and ContactForm entity, so what im thinking is to create a contactform entity and give it to the entityFormBuilder->getForm( $contactFormEntity)

My current code is:

<?php


/**
 * @file
 * Contains Drupal\pid_contactform_block\Plugin\Block\TellUsYourStoryBlock
 */

namespace Drupal\pid_contactform_block\Plugin\Block;

use Drupal\Core\Block\BlockBase;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Class TellUsYourStoryBlock
 * @package Drupal\pid_contactform_block\Plugin\Block
 * @Block(
 *     id = "tell_us_your_story_block_id",
 *     admin_label = "Tell us your story block",
 *     module = "pid_contactform_block"
 * )
 */
class TellUsYourStoryBlock extends BlockBase implements ContainerFactoryPluginInterface {
    protected $entityFormBuilder;

public function __construct(array $configuration, $plugin_id, $plugin_definition, $entityFormBuilder) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->entityFormBuilder = $entityFormBuilder;
}
/**
 * Builds and returns the renderable array for this block plugin.
 *
 * If a block should not be rendered because it has no content, then this
 * method must also ensure to return no content: it must then only return an
 * empty array, or an empty array with #cache set (with cacheability metadata
 * indicating the circumstances for it being empty).
 *
 * @return array
 *   A renderable array representing the content of the block.
 *
 * @see \Drupal\block\BlockViewBuilder
 */
public function build()
{
    return $this->entityFormBuilder->getForm();

}

/**
 * Creates an instance of the plugin.
 *
 * @param \Symfony\Component\DependencyInjection\ContainerInterface $container
 *   The container to pull out services used in the plugin.
 * @param array $configuration
 *   A configuration array containing information about the plugin instance.
 * @param string $plugin_id
 *   The plugin ID for the plugin instance.
 * @param mixed $plugin_definition
 *   The plugin implementation definition.
 *
 * @return static
 *   Returns an instance of this plugin.
 */
public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition)
{
    return new static(
        $configuration,
        $plugin_id,
        $plugin_definition,
        $container->get('entity.form_builder')
    );
}

}

My question is basically: -am i doing it the right way? -how do i initialize the ContactForm entity correctly, if i am right, should i just import it or should i require it through a service or something? -if im not right, do you have any idea how i should do it then???