Connect to container from another docker-compose.yml file

[Ravira43]

Hi yall,

I'm trying to connect a container from a different docker-compose.yml to my gluetun docker container (described here: https://github.com/qdm12/gluetun-wiki/blob/main/setup/connect-a-container-to-gluetun.md).
Unfortunately I'll always receive the error "service ***** depends on undefined service gluetun: invalid compose project"

If I put the service into the same docker-compose.yml it's working fine.

Already found and tried this #356 without success.

That's how I'm trying to connect:

network_mode: container:gluetun
depends_on:
  gluetun:
    condition: service_healthy

Any help is appreciated