Using a GitHub deploy key instead of a personal access token (PAT) for accessing a private repository in Prefect is not directly supported. The documentation suggests using PATs for private repositories, and there's no explicit mention of deploy keys being supported for Prefect deployments. Deploy keys are specific to repositories and provide read (and optionally write) access, but Prefect's current setup seems to favor PATs for authentication.
However, an issue on GitHub mentions the request to support deploy keys, especially for platforms like Gitea. This indicates there might be interest in such a feature, but it's not currently available in Prefect.
For now, you will need to use a PAT or explore alternative methods like using a Secret block to store credentials securely. You can reference these blocks in your deployment configuration.
For more details, you can review the Prefect documentation
here and the related GitHub issue
here.
If you have further questions or need assistance with a specific setup, feel free to ask.