Local CDN with WP Redis

Hello guys,

I'm trying to setup a local CDN on a website.
I've updated the settings for the website configuration with ee site edit example.com.
The setting i added:

subs_filter https://uberkino.ro/wp-content/uploads https://cdn.uberkino.ro/wp-content/uploads;

I also set the uploads folder in wp-config:

define('UPLOADS', 'cdn/uberkino.ro/wp-content/uploads');

However, nothing is uploaded to cdn.uberkino.ro

Any ideas?

Thanks in advance.