List Slim 4 registered routes

slim4-routes.php

<?php

// Slim 4.

$routes = $app->getRouteCollector()->getRoutes();
$output = [];

/** Slim\Routing\Route $route */
foreach ($routes as $route) {
    $output[] = [
        'methods' => $route->getMethods(),
        'pattern' => $route->getPattern(),
        'name' => $route->getName(),
        'identifier' => $route->getIdentifier(),
        'action' => is_object($route->getCallable()) ? get_class((object) $route->getCallable()) : '[closure]',
    ];
}

var_dump($output);