How to Change the Default Media Upload Location

the easiest way I’ve found is to use your subdomain as a CDN

I do that using
https://www.ads-software.com/extend/plugins/w3-total-cache/

Which has all sorts of awesomeness to make your site faster.

I believe there are other CDN plugins which will let you use a personal subdomain as CDN if w3 is a bit too much

I found this solution and works! ??

https://www.wpbeginner.com/wp-tutorials/how-to-change-the-default-media-upload-location-in-wordpress-3-5/

Hello I wrote a small plugin for the new facilities WordPress 3.5.
You can directly modify the domain or subdomain
https://www.ads-software.com/extend/plugins/wp-original-media-path/