Alternatively, the order save could generate a FHIR R4 ServiceRequest Resource for direct transmission.
FHIR Task bundled order is sent to the IOL and consists of a FHIR R4 Task Resource and a referenced FHIR R4 Patient Resource (example). Task status is aligned with the FHIR workflow communication pattern found here
Alternatively a FHIR R4 ServiceRequest and Patient Resource bundle could be sent
Bundled order is routed through the IOL to both the SHR and the LIS
Save Order and Update Order Status
FHIR R4 Task Resource Status is updated locally to either rejected or accepted. A FHIR R4 ServiceRequest Resource (example) is created for order processing with a reference to the associated task. EMR test requests and LIS orders are matched based on LOINC codes.
Alternatively, a ServiceRequest with a link to the referenced ServiceRequest could be populated.
Update Task Resource Status from  is sent to the IOL
Alternatively, this could be an update to a FHIR R4 ServiceRequest resource
IOL routes the updated FHIR R4 Tasks to the SHR and the EMR
See transaction options 
FHIR task status updated locally
See transaction options