You need to put the uploads/images somewhere that they can be accessed from inside the container. Maybe in /var/discourse/shared/standalone/uploads/ and then they’ll be in /shared/uploads inside the container. You get into the container with
cd /var/discourse
./launcher enter app
Then you’ll be in /var/www/discourse and see the scripts.
If you’ve a budget, I can set things up for you. See Redirecting…