This is probably something not yet implemented. If you'd like to provide a feature request, it'd be better to raise an issue in the source repo (https://github.com/danny0838/webscrapbook/issues) or send an email, and provide more details (e.g. Do you use a backend server? What is your use case and intention?) as it's not easy to discuss in this Addon site (we won't receive any notification from an update of a comment).

cf. thread of the original request: https://github.com/danny0838/webscrapbook/issues/8