What does <container ###> mean

im trying to run a container to open a jupyter notebook, and the guideline is telling me to run
<container ###> cd /my_mount
In this case, what would container ### be? Thank you

The way the post is written, it expects the reader to have full knowledge of the context, and as such should have been posted in a Jupyter notebook forum. There is no way for anyone else to understand the post.

My best effort guess is that it means the command should be executed inside a container.