There is an .env.example file. Make your changes there and rename it to .env The start the image.
$ docker compose up -d
When started the first time browse to the Hub at http://localhost:8090 and create a token and a key.
Then stop the container:
$ docker compose down
Add these to you .env and rebuild/restart the conainer:
$ docker compose up -d --build --force-recreate
For further documentation see the official guide at https://beszel.dev/.
Deployment is done by Github actions.