API Platform custom operation response - dompdf

Question

I need to return a PDF file using DomPDF, from a custom operation in API Platform, for exporting the entity data. After spending time studying the documentation, and doing many searches on the internet, I came up with a setup, but it still doesn't work.
Here's my entity
namespace App\Entity\ProjectManagement;
...
/**
* Class Ticket
* #package App\Entity\ProjectManagement
* #ApiResource(
* routePrefix="/projmgmt",
* shortName="Ticket",
* normalizationContext={"groups"={"appentity:read", "appgeneratedcodeentity:read", "ticket:read"}},
* denormalizationContext={"groups"={"appentity:write", "appgeneratedcodeentity:write", "ticket:write"}},
* itemOperations={
* "get", "put", "patch", "delete",
* "export"={
* "method"="GET",
* "path"="/tickets/{id}/export",
* "controller"=ExportTicketAction::class,
* "openapi_context"={
* "responses"={
* "200"={
* "content"={
* "application/pdf"={
* "schema"={
* "type"="string",
* "format"="binary",
* }
* }
* }
* }
* }
* }
* }
* }
* )
* #ApiFilter(PropertyFilter::class)
* #UniqueEntity(fields="code", message="The code {{ value }} already exists in the DB.")
* #ORM\Table(name="gestop_projmgmt_ticket")
* #ORM\Entity(repositoryClass=TicketRepository::class)
*/
class Ticket
{
...
and here's my controller
namespace App\Controller\ProjectManagement;
...
/**
* Class ExportTicketAction
* #package App\Controller\ProjectManagement
*/
final class ExportTicketAction extends AppController
{
/**
* #param Ticket $ticket
* #return Response
*/
public function __invoke(Ticket $ticket): Response
{
$dompdf = (new Dompdf((new Options())
->set('defaultFont', 'Arial')
->set('isPhpEnabled', true)
->set('isRemoteEnabled', true)))
->setPaper('A4', 'portrait');
$dompdf->loadHtml($this->renderView('/reports/projmgmt/ticket.html.twig', ['ticket' => $ticket]));
$dompdf->render();
return new Response($dompdf->output(), 200, ['Content-Type' => 'application/pdf']);
}
}
At the moment the Twig template doesn't have much information, I just need it to work and then I start designing it.
{% extends 'report.html.twig' %}
{% block report_title %}{{ 'gestop.entity.projmgmt.ticket'|trans }}{% endblock %}
{% block report_css %}
<style>
body { font-family: Arial, Helvetica, sans-serif; }
header { text-align: center; }
footer { font-size: small; }
</style>
{% endblock %}
{% block report_header %}{{ 'gestop.entity.projmgmt.ticket'|trans }}{% endblock %}
{% block report_content %}
<p>test</p>
{% endblock %}
Please, what am I doing wrong, or am I even on the right track?