I have just purchased the CKEditor Instant Image Upload add-on and am unable to get it to function correctly. I can see the new button in my editor and when I click it a pop up window opens allowing me to choose a file. When I select a file however and go to check the server - there has been nothing uploaded. I have kept 'config.php' as default (i.e. haven't touched it) and have amended 'config.js' as per instructions. I'm obviously doing something wrong and could do with some help. This is my amended 'config.js' - any help would be appreciated.

Hello, please check permissions in the server folder. Also to tell you more I need to see client side info (errors from Console tab in browser's debugger and request log to `uploader.php` from Network tab; and the error log from PHP's `error.log` if you get 500-th error).