ERROR: Version in "./docker-compose.yml" is unsupported.

Getting the following error on "init" and "start":

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/

Start with docker-compose.yml and reproduce the error by running the init and start commands. Check the Compose file version against the supported format; done means both commands run without the unsupported-version error.

Written by the indexing model from the issue text.