Best Practive to use Docker Network fails

[excelsi]

I tried this recommendation
https://nginxproxymanager.com/advanced-config/#best-practice-use-a-docker-network

Resulting in this Docker Compose File:

version: '3.8'
services:
  app:
    image: 'jc21/nginx-proxy-manager:latest'
    restart: unless-stopped
    ports:
      # These ports are in format <host-port>:<container-port>
      - '80:80' # Public HTTP Port
      - '443:443' # Public HTTPS Port
      - '81:81' # Admin Web Port
networks:
  default:
    external: true
    name: scoobydoo

I got this error :
ERROR: The Compose file './docker-compose.yml' is invalid because:
networks.default value Additional properties are not allowed ('name' was unexpected)

These are my networks:
NETWORK ID NAME DRIVER SCOPE
cc876b184788 bridge bridge local
774e845c5f59 host host local
a736dc513621 none null local

Any help?
Thanks!

[excelsi]

I also created the Network with:
docker network create scoobydoo

NETWORK ID NAME DRIVER SCOPE
cc876b184788 bridge bridge local
774e845c5f59 host host local
a736dc513621 none null local
b8e7cda30a0f scoobydoo bridge local

But still got the same error as before...
Maybe a syntax error...

[excelsi]

Or its the Version of my Docker Compose i changed it now to Version 3.8 as mentioned in the example...

version: '3.8'
services:
app:
image: 'jc21/nginx-proxy-manager:latest'
restart: unless-stopped
ports:
# These ports are in format :
- '80:80' # Public HTTP Port
- '443:443' # Public HTTPS Port
- '81:81' # Admin Web Port
networks:
default:
external: true
name: scoobydoo

But then at exection time i get that this version is unsupported:

ERROR: Version in "./docker-compose.yml" is unsupported. You might be seeing this error because you're using the wrong Compose file version. Either specify a supported version (e.g "2.2" or "3.3") and place your service definitions under the services key, or omit the version key and place your service definitions at the root of the file to use version 1.
For more on the Compose file format versions, see https://docs.docker.com/compose/compose-file/

[excelsi]

Found the solution finally ;D
I used docker-compose command instead of docker compose