@ dev, пожалуйста, найдите код ниже для ваших нужд
// 1 check if your input from the form is not empty
if ((isset($_FILES['file']))){
// 2. files inside the session
$_SESSION['FILES'] = $_FILES;
// 3. your path
$PATH = $_SERVER["DOCUMENT_ROOT"]."/mobile_image/transfer/";
// 4. temporary name -> optional step but recommended
$TEMP_NAME = explode(".",$_FILES["file"]);
// 5. new name of the file
$NAME_NEW = substr(number_format(time() * rand(),0,'',''),0,20) . '.' .end($TEMP_NAME);
$UPLOAD_FILE = $PATH . basename($NAME_NEW);
// 6. check before moving the file that is not empty
if (isset($UPLOAD_FILE)) {
move_uploaded_file($_FILES['file'], $PATH); }
// 7. custom errors
$json = array();
$json['status'] = "OK";
$json['message'] = 'File moved successfully';
echo json_encode($json);
}else{
// 7. custom errors
$json = array();
$json['status'] = "NO FILE";
$json['message'] = 'No files found';
echo json_encode($json);
}