MedicationOrder - is there an example or way to support Signing of orders

MedicationOrder - is there an example or way to support Signing of orders

We have millions of orders in our EHR. Not all of them are signed, as physicians can call orders in and the nurse enters them in the EHR. We have a requirement to implement a SMART FHIR app to present physicians with all the orders they need to sign. Has anyone implemented or thought of implementing Order Signing via FHIR? Via Order, Workflow, or combo resource and operation.

Thank you

Radu