I'm trying to understand the compose override

I’m teaching myself Docker/Astronomer for my first project at my new internship, and I need to add a volume to handle downloads from selenium. I’m assuming it needs tagged onto the scheduler so I tried the following code in docker-compose.override.yml mirroring the style that is in the composeyml.go on github.

version: ‘2’
- {{ .AirflowHome }}/downloads:/usr/local/airflow/downloads:{{ .MountLabel }}

when I try to start astro it does not like this approach though. It doesn’t want a space between - {{, and once thats resolved it doesn’t seem to like the {{}} but those are in the astro documentation. Here are the exact errors for both. I hope someone has some insight, because I’m not finding anything online to help. Thanks in advance.

Error creating docker-compose project: yaml: line 4: did not find expected ‘-’ indicator

Error creating docker-compose project: Service ‘scheduler’ configuration key ‘volumes’ contains an invalid type, it should be an array.