This image packages the Heroku CLI inside an Alpine Linux based Docker container. The version will track that of the Heroku CLI.
The easiest way to use this would be to use your Heroku API key or an OAuth authorization token set as the HEROKU_API_KEY environment variable.
docker run --rm algonauti/heroku-cli version
# heroku/7.47.3 linux-x64 node-v14.15.1
# API key/OAuth token method
docker run --rm -e HEROKU_API_KEY="api123" algonauti/heroku-cli list