I have tried and it will only put files into the parent folder, not a new folder. i Also cannot get it to also create the folder.
move_uploaded_file($_FILES['file']['tmp_name'][$i],'upload/'.$i); }
An answer from another question. Grant the www-user write access to the folder where you are trying to write to.
sudo chown -R www-data:www-data /var/www/example.com/uploads
sudo chmod -R 770 /var/www/example.com/uploads
source ~ https://superuser.com/questions/646062/granting-write-permissions-to-www-data-group