Ingesting FHIR orders with sample collection appointment date/time for phlebotomy workflow

We are using FHIR to send test orders placed in our EMR over to OpenELIS. We have a workflow where clinicians schedule sample collection appointments, and we would like phlebotomists to manage sample collection directly in OpenELIS.

However, we haven’t found a way to ingest external test orders in an AwaitingSpecimen status alongside a scheduled sample collection appointment timestamp. Our goal is for phlebotomists to see incoming external orders sorted by appointment date and time to organize their sample collections efficiently.

We need to create orders with an AwaitingSpecimen status that include a sample collection appointment date/time. Because the FHIR Appointment resource is not supported in the OpenELIS FHIR configuration, how can we pass collection schedule details with external orders so phlebotomists can view them sorted by appointment time?