Unable to upload files to EC2 Amazon Linux 2023

In what directory is this PHP script running?
This PHP script creates a directory called "/uploads/" in the same directory as the script and saves images in that directory.
I think you are misunderstanding something.

I modified the code as below.
I think the cause was that there was no "/uploads/" directory in the "/tmp" directory.
So I modified the code to create the directory if it doesn't exist.

<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

    $currentDirectory = getcwd();
    $uploadDirectory = "/uploads/";

    if (!file_exists($currentDirectory . $uploadDirectory)) {
      mkdir($currentDirectory . $uploadDirectory, 0755, true);
    }

    $errors = []; // Store errors here

    $fileExtensionsAllowed = ['jpeg','jpg','png', 'txt']; // These will be the only file extensions allowed 

    $fileName = $_FILES['the_file']['name'];
    $fileSize = $_FILES['the_file']['size'];
    $fileTmpName  = $_FILES['the_file']['tmp_name'];
    $fileType = $_FILES['the_file']['type'];
    $fileExtension = strtolower(end(explode('.',$fileName)));

    $uploadPath = $currentDirectory . $uploadDirectory . basename($fileName); 

    if (isset($_POST['submit'])) {

      if (! in_array($fileExtension,$fileExtensionsAllowed)) {
        $errors[] = "This file extension is not allowed. Please upload a JPEG or PNG file";
      }

      if ($fileSize > 4000000) {
        $errors[] = "File exceeds maximum size (4MB)";
      }

      if (empty($errors)) {
        $didUpload = copy($fileTmpName, $uploadPath);

        if ($didUpload) {
          echo "The file " . basename($fileName) . " has been uploaded";
        } else {
          echo "An error occurred. Please contact the administrator.";
        }
      } else {
        foreach ($errors as $error) {
          echo $error . "These are the errors" . "\n";
        }
      }

    }
?>