routes.php

<?php

$app->get('/amka/{amka}/{surname}[/{extended}]', '\Gr\Gov\Minedu\Osteam\Slim\App:validateAmka')
    ->setName('amkaext');
$app->get('/amka/{amka}/{surname}/', '\Gr\Gov\Minedu\Osteam\Slim\App:validateAmka')
    ->setName('amka');
$app->get('/amka/{amka}[/]', '\Gr\Gov\Minedu\Osteam\Slim\App:isAmka')
    ->setName('amkas');

$app->any('/[{anythingelse}]', function ($request, $response, $args) {
    $this->logger->info("Void response, no action route was enabled");
    return $response->withJson([
                'message' => 'Δεν αναγνωρίστηκε το αίτημα σας',
                'in' => var_export($args, true)
                    ], 404
    );
});