To use Docker, in QNAP Container Station you can create an app, and then paste in the storage node docker compose config. This is how I run my node. I attached a screenshot here to show you what I mean:
You will need to ensure /share/Container/storj/storage and /share/Container/storj/identity go to the right place on the storage. If you SSH into the NAS it can be helpful to locate these paths.
Alternatively you can follow the Docker steps here and do it all while in an SSH session.