The first commenter has succinctly pointed you in the right direction - the dataFrom field requires the secret data to be in JSON format [1]. Since your data is plain text you got that general Go error.

To get the raw secret value you can indeed use remoteRef field as shown in this example [2].

[1] https://external-secrets.io/latest/guides/all-keys-one-secret/\ [2] https://external-secrets.io/latest/provider/google-secrets-manager/#creating-external-secret