Why does Mamp throw an error when implementing a controller?

Question

PHP

There is a controller implementation in php.
When trying to start, MAMP throws an error

Warning: require_once(/Users/klen/PhpstormProjects/myproject.loc/www/../src/MyProject\Controllers\MainController.php): failed to open stream: No such file or directory in / Users/klen/PhpstormProjects/myproject.loc/www/index.php on line 6

Fatal error: require_once(): Failed opening required '/Users/klen/PhpstormProjects/myproject.loc/www/../src/MyProject\Controllers \MainController.php' (include_path='.:/Applications/MAMP/bin/php/php7.3.9/lib/php') in /Users/klen/PhpstormProjects/myproject.loc/www/index.php on line 6

Problem in this code:
spl_autoload_register(function (string $className) {
require_once __DIR__ . '/../src/' . $className . '.php';
});

What could be the problem, tell me please?