docker-compose.yml doesn't work

[spam0115]

When using the first docker-compose.yml shown in your readme, I get the following error:
validating /home/yournamehere/papermerge/docker-compose.yml: services.web.environment must be a mapping

Here is the yml that produced that error:
version: "3.9"

x-backend: &common
image: papermerge/papermerge:3.0.3
environment:
PAPERMERGE__SECURITY__SECRET_KEY: 12345
PAPERMERGE__AUTH__USERNAME: john
PAPERMERGE__AUTH__PASSWORD: hohoho
PAPERMERGE__DATABASE__URL: postgresql://scott:tiger@db:5432/mydatabase
PAPERMERGE__REDIS__URL: redis://redis:6379/0
volumes:
- index_db:/core_app/index_db
- media:/core_app/media
services:
web:
<<: *common
ports:
- "12000:80"
depends_on:
- redis
- db
worker:
<<: *common
command: worker
redis:
image: redis:6
db:
image: bitnami/postgresql:16.1.0
volumes:
- postgres_data:/var/lib/postgresql/data/
environment:
POSTGRESQL_USER: scott
POSTGRESQL_PASSWORD: tiger
POSTGRESQL_POSTGRES_PASSWORD: tiger
POSTGRESQL_DATABASE: mydatabase
volumes:
postgres_data:
index_db:
media:

Chatgpt fixed it into the following format for me. It worked. Chatgpt said the problem was "the environment section is not correctly formatted as a mapping (key-value pairs). In YAML, mappings are represented with a colon (:) followed by a space, and lists are represented with a hyphen (-)."

version: "3.9"

x-backend: &common
image: papermerge/papermerge:3.0.3
environment:
PAPERMERGE__SECURITY__SECRET_KEY: "12345"
PAPERMERGE__AUTH__USERNAME: "john"
PAPERMERGE__AUTH__PASSWORD: "hohoho"
PAPERMERGE__DATABASE__URL: "postgresql://scott:tiger@db:5432/mydatabase"
PAPERMERGE__REDIS__URL: "redis://redis:6379/0"
volumes:
- index_db:/core_app/index_db
- media:/core_app/media

services:
web:
<<: *common
ports:
- "12000:80"
depends_on:
- redis
- db

worker:
<<: *common
command: worker

redis:
image: redis:6

db:
image: bitnami/postgresql:16.1.0
volumes:
- postgres_data:/var/lib/postgresql/data/
environment:
POSTGRESQL_USER: scott
POSTGRESQL_PASSWORD: tiger
POSTGRESQL_POSTGRES_PASSWORD: tiger
POSTGRESQL_DATABASE: mydatabase

volumes:
postgres_data:
index_db:
media: