I'm sorry, but the knowledge sources provided do not contain explicit, step-by-step instructions or configuration keys for enabling or configuring TLS (HTTPS) for Ory Keto specifically. While there are detailed TLS setup guides for Ory Kratos and Ory Hydra, similar documentation for Ory Keto is not included in the sources above. However, the Ory Keto configuration reference does mention that all configuration values can be set using environment variables or a config file, and it links to further documentation for configuration, but the actual TLS-related keys or examples are not present in the provided content. For precise instructions, you would need to consult the official Ory Keto documentation or configuration reference directly for the most up-to-date and detailed guidance on enabling TLS for Ory Keto servers [Ory Keto Configuration Reference](https://www.ory.sh/docs/keto/reference/configuration).