put https://fhir-api.zapehr.com/r4b/ObservationDefinition/
ObservationDefinition on the FHIR specification website.
Set of definitional characteristics for a kind of observation or measurement produced or consumed by an orderable health care service.
The body should be a valid FHIR object for ObservationDefinition.
Here is an example:
{
  "resourceType": "ObservationDefinition",
  "id": "example",
  "text": {
    "status": "generated",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\"><p><b>Generated Narrative with Details</b></p><p><b>id</b>: example</p><p><b>code</b>: Glucose [Moles/volume] in Blood <span>(Details : {LOINC code '15074-8' = 'Glucose [Moles/volume] in Blood', given as 'Glucose [Moles/volume] in Blood'})</span></p></div>"
  },
  "code": {
    "coding": [
      {
        "system": "http://loinc.org",
        "code": "15074-8",
        "display": "Glucose [Moles/volume] in Blood"
      }
    ]
  }
}
You can reference the FHIR documentation to determine the format for ObservationDefinition.
