You could make a new page in the Magento backend in Content->pages in which you insert the contact block in the page content:
{{block class="Magento\Contact\Block\ContactForm" name="contactForm" template="Magento_Contact::form.phtml"}}
In order to make the page visible in your header, you can make an observer on the page block topmenu as follows:
<event name="page_block_html_topmenu_gethtml_before">
<observer name="cc_add_contact" instance="Vendor\Modulename\Observer\Topmenu" />
</event>
The observer would look something like this:
<?php
namespace Vendor\Module\Observer;
use Magento\Framework\Event\Observer as
EventObserver;
use Magento\Framework\Data\Tree\Node;
use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\UrlInterface;
use Magento\Catalog\Model\CategoryRepository;
class Topmenu implements ObserverInterface
{
/**
* @var UrlInterface
*/
protected $url;
/**
* @var CategoryRepository
*/
protected $categoryRepository;
/**
* Topmenu constructor.
* @param UrlInterface $url
* @param CategoryRepository $categoryRepository
*/
public function __construct
(
UrlInterface $url,
CategoryRepository $categoryRepository
)
{
$this->url = $url;
$this->categoryRepository = $categoryRepository;
}
/**
* @param EventObserver $observer
* @return $this
*/
public function execute(EventObserver $observer)
{
/** @var \Magento\Framework\Data\Tree\Node $menu */
$menu = $observer->getMenu();
$tree = $menu->getTree();
$data = [
'name' => __('Feedback'),
'id' => 'feedback',
'url' => '/feedback',
'is_active' => $this->isActiveFeedback()
];
$node = new Node($data, 'id', $tree, $menu);
$menu->addChild($node);
return $this;
}
/**
* @return int
*/
public function isActiveFeedback(){
$url = $this->url->getCurrentUrl();
if (substr($url,-9)=="/feedback"){
return 1;
}
return 0;
}
}