Hi Medplum team, I have a FHIR related question about the ChargeItemDefinition resource. Is it possible for the instance element to be a reference of HealthCareService? I can see in Medplum documentation the listed options as of now are: Medication, Substance, and Device so I wanteed to see if HealthCareService is also an option here. Thank you!

That might be technically correct but I think we haven't largely seen it used in practice. Here's a sample of what we recommend https://github.com/medplum/medplum/blob/main/examples/medplum-provider/src/data/simple-initial-visit-bundle.json