Help with Hardware Acceleration

[foxhoundxgenome]

I have finally got everything to work both locally and remotely, so now I would like to enable hardware acceleration, but am having some trouble.

From the official Jellyfin documentation here (https://jellyfin.org/docs/general/admini...ualization), I have tried:

Code:

docker run -d \
--name=jellyfin \
--volume /path/to/config:/config \
--volume /path/to/cache:/cache \
--volume /path/to/media:/media \
--user 1000:1000 \
--group-add="122" \ # Change this to match your "render" host group id and remove this comment
--net=host \
--restart=unless-stopped \
--device /dev/dri/renderD128:/dev/dri/renderD128 \
jellyfin/jellyfin

*I replaced the volumes and the render group ID accordingly, and removed the comment for the group-add line
However, after entering the above in a Stack within Portainer, I receive this error message:

Deployment error

failed to deploy a stack: Top-level object must be a mapping

These are my specs:
Running Jellyfin in a Docker container via Portainer
OS: Ubuntu Server
GPU: Intel CoffeeLake-S GT2 [UHD Graphics 630]

Does anyone know what I'm doing wrong?
I have also tried the following solutions with no success:
https://www.youtube.com/watch?v=_RfH65swYNo
https://www.youtube.com/watch?v=VHXefJ7Ne6I