How

When you send the patient resource, you will need to send in two identifiers:
1. The logical id that you assign
2. The patient’s business identifier (e.g. NHS number)
Assign the patient a logical id so that it can be referenced in other resources.
The logical id of an organization that already exists in the upstream data store must be referenced as the Patient.managingOrganization element.
At a minimum, include first name, last name, dob, gender along with the identifier.
POST https://<client>.fhir-api.sandbox.patientsknowbest.com/fhir/Patient

Very basic Patient resource example:

{
  "resourceType": "Patient",
  "id": "<Client assigned patient logical id>",
  "identifier": [
    {
      "system": "https://fhir.nhs.uk/Id/nhs-number",
      "value": "9571270652"
    }
  ],
  "name": [
    {
      "family": "Lyons",
      "given": [
        "Iris"
      ],
      "prefix": [
        "Ms."
      ]
    }
  ],
  "telecom": [
    {
      "system": "phone",
      "value": "07787893978"
    }
  ],
  "gender": "female",
  "birthDate": "1957-04-21",
  "address": [
    {
      "line": [
        "724 Joceko Road"
      ],
      "city": "Tuses",
      "state": "Carihofox",
      "postalCode": "FJ113FZ",
      "country": "GBR"
    }
  ],
  "managingOrganization": {
    "reference": "Organization/<client assigned organization logical id>"
  }
}

Creating FHIR Patients

How