class EntityCreateAccessCheck

class EntityCreateAccessCheck implements AccessInterface {
    
    /**
     * The entity type manager service.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The key used by the routing requirement.
     *
     * @var string
     */
    protected $requirementsKey = '_entity_create_access';
    
    /**
     * Constructs an EntityCreateAccessCheck object.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager service.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager) {
        $this->entityTypeManager = $entity_type_manager;
    }
    
    /**
     * Checks access to create the entity type and bundle for the given route.
     *
     * @param \Symfony\Component\Routing\Route $route
     *   The route to check against.
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   The parametrized route.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The currently logged in account.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The access result.
     */
    public function access(Route $route, RouteMatchInterface $route_match, AccountInterface $account) {
        [
            $entity_type,
            $bundle,
        ] = explode(':', $route->getRequirement($this->requirementsKey) . ':');
        // The bundle argument can contain request argument placeholders like
        // {name}, loop over the raw variables and attempt to replace them in the
        // bundle name. If a placeholder does not exist, it won't get replaced.
        if ($bundle && str_contains($bundle, '{')) {
            foreach ($route_match->getRawParameters()
                ->all() as $name => $value) {
                $bundle = str_replace('{' . $name . '}', $value, $bundle);
            }
            // If we were unable to replace all placeholders, deny access.
            if (str_contains($bundle, '{')) {
                return AccessResult::neutral(sprintf("Could not find '%s' request argument, therefore cannot check create access.", $bundle));
            }
        }
        return $this->entityTypeManager
            ->getAccessControlHandler($entity_type)
            ->createAccess($bundle, $account, [], TRUE);
    }

}