Help With Jinja Statement For Appending To List

I’m having a problem with Jinja Statements, and having it append to a list.

I have an existing list of VLANs that I’m trying to sort into individual lists but the statement I’m using isn’t appending, but rather creating separate lists. Can you point out what I’m doing wrong please so that I end up with the ‘Desired Result’ below?

List of VLANs