Are you able to ssh into a QNAP NAS? I would assume you can. If so, try docker ps and see what it says. If it gives you a permissions error, try sudo docker ps. If either works (even if it lists no processes), then you can use docker commands. The following is a script that you can run. If you needed sudo to run the test command earlier, then run the script using sudo. Read the comments before running the script. There are things you need to modify before the first time you run the script, and after the first time.
#!/bin/sh
# You can save this as a script: update_msr.sh
# Set permissions: chmod 755 update_msr.sh
#
# Before running this, stop and delete the existing container yourself.
# After you have started MSR for the first time using
# this script, you can uncomment the two docker
# commands below and the script will do it for you from then.
#docker stop reactor
#docker container rm reactor
#
# Pull the new image:
docker pull toggledbits/reactor:latest-generic-amd64
#
# Create and start the new container: Adjust TZ as needed, and
# provide the path to your Reactor data directory where shown:
docker run --name reactor -d --restart on-failure -p 8111:8111 \
-e 'TZ=America/New_York' \
-v /PATH/TO/YOUR/DATA:/var/reactor \
--mount type=bind,src=/etc/localtime,target=/etc/localtime \
--network host \
toggledbits/reactor:latest-generic-amd64