SlimExceptionHttpNotFoundException

$app = AppFactory::create();

$app->setBasePath("/myapp/api"); // /myapp/api is the api folder (http://domain/myapp/api)

RewriteEngine on  
RewriteCond %{ENV:REDIRECT_STATUS} !200 
RewriteRule ^api/(.*)$ api/index.php/$1

try {
    $app->run();     
} catch (Exception $e) {    
  // We display a error message
  die( json_encode(array("status" => "failed", "message" => "This action is not allowed"))); 
}

$app = AppFactory::create();

$app->addErrorMiddleware(true, true, true);

$app->setBasePath("/myapp/public/index.php");

// Define app routes
$app->get('/hello/{name}', function (Request $request, Response $response, $args) {
    $name = $args['name'];
    $response->getBody()->write("Hello, $name");
    return $response;
});

$app->get('/hello/{name}', function (Request $request, Response $response, array $args) { ... }

$app->get('/[my-appname]/public/hello/{name}', function (Request $request, Response $response, array $args) { .. }

 <?php
 use Psr\Http\Message\ResponseInterface as Response;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use Slim\Factory\AppFactory;

 require __DIR__ . '/../vendor/autoload.php';


 $app = AppFactory::create();

//here i used the url change to your project name on [my-appname]
 $app->get('/[my-appname]/public/hello/{name}', function (Request $request, 
 Response $response, array $args) {
    $name = $args['name'];
    $response->getBody()->write("Hello, $name");
    return $response;
 });

$app->run();

composer require slim/slim:3.*

<?php
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
//use Slim\Factory\AppFactory;

require '../vendor/autoload.php';

$app = new \Slim\App;

$app->get('/hello/{name}', function (Request $request, Response $response, array $args) {
    $name = $args['name'];
    $response->getBody()->write("Hello, $name");
    return $response;
});

$app->run();