What is the syntax error in my docker compose file?

I copied authoritative content at https://github.com/Kong/docker-kong/blob/master/compose/docker-compose.yml

```
version: '3.9'

x-kong-config: &kong-env
KONG_DATABASE: ${KONG_DATABASE:-off}
KONG_PG_DATABASE: ${KONG_PG_DATABASE:-kong}
KONG_PG_HOST: db
KONG_PG_USER: ${KONG_PG_USER:-kong}
KONG_PG_PASSWORD_FILE: /run/secrets/kong_postgres_password

volumes:
kong_data: {}
kong_prefix_vol:
driver_opts:
type: tmpfs
device: tmpfs
kong_tmp_vol:
driver_opts:
type: tmpfs
device: tmpfs

networks:
kong-net:
external: false

services:
kong-migrations:
image: "${KONG_DOCKER_TAG:-kong:latest}"
command: kong migrations bootstrap
profiles: ["database"]
depends_on:
- db
environment:
<<: *kong-env
secrets:
- kong_postgres_password
networks:
- kong-net
restart: on-failure

kong-migrations-up:
image: "${KONG_DOCKER_TAG:-kong:latest}"
command: kong migrations up && kong migrations finish
profiles: ["database"]
depends_on:
- db
environment:
<<: *kong-env
secrets:
- kong_postgres_password
networks:
- kong-net
restart: on-failure

kong:
image: "${KONG_DOCKER_TAG:-kong:latest}"
user: "${KONG_USER:-kong}"
environment:
<<: *kong-env
KONG_ADMIN_ACCESS_LOG: /dev/stdout
KONG_ADMIN_ERROR_LOG: /dev/stderr
KONG_PROXY_LISTEN: "${KONG_PROXY_LISTEN:-0.0.0.0:8000}"
KONG_ADMIN_LISTEN: "${KONG_ADMIN_LISTEN:-0.0.0.0:8001}"
KONG_ADMIN_GUI_LISTEN: "${KONG_ADMIN_GUI_LISTEN:-0.0.0.0:8002}"
KONG_PROXY_ACCESS_LOG: /dev/stdout
KONG_PROXY_ERROR_LOG: /dev/stderr
KONG_PREFIX: ${KONG_PREFIX:-/var/run/kong}
KONG_DECLARATIVE_CONFIG: "/opt/kong/kong.yaml"
secrets:
- kong_postgres_password
networks:
- kong-net
ports:
# The following two environment variables default to an insecure value (0.0.0.0)
# according to the CIS Security test.
- "${KONG

By default, some IDEs, such as Visual Code, will look for a standard Schema of the file type "docker-compose.yaml" or "docker-compose.yml".

Example

For example, I have the most up-to-date versions of the linter plugins, and I haven't had any problems with the file. I would recommend that you update your plugins or IDE.

StackExchange DevOps Q#18383, answer score: 1