Hi,
after a lot of struggles, I found out how to get the docker working on Unraid.
You set your parameters, then switch to the advanced view.
Take the Container Path from NOTES
In the 'Post Arguments' field, add:
--workspace=CONTAINER_NOTES_PATH --accessAuthCode=YOUR_WEBUI_PASSWORD
in my case:
--workspace=/root/Documents/SiYuan/data/ --accessAuthCode=pass123
Normally, you should have a working Siyuan.