Comment 1 for bug 1958253

The error is because juju is expecting a yaml file or snippet with content like

registrypath: someimagepath@sha256:beef-deed
username: fred
password: secret

The yaml is used to override the default oci image details published with the charm.

ie the image details are specified using juju resources, but those resources are not the image blobs, but rather a yaml/json snippet with details of how to access the required image from a registry.

The error message could definitely be improved.