when I tried it I always get ->

{
  "resourceType": "Bundle",
  "type": "transaction-response",
  "entry": [
    {
      "response": {
        "outcome": {
          "resourceType": "OperationOutcome",
          "id": "not-found",
          "issue": [
            {
              "severity": "error",
              "code": "not-found",
              "details": {
                "text": "Not found"
              }
            }
          ]
        },
        "status": "404"
      }
    }
  ]
}

which makes me think -> url": "PractitionerRole?identifier=http://hl7.org/fhir/sid/us-npi|123" is probably not supported in medplum I found and example of this syntax here -> https://smilecdr.com/docs/fhir_standard/transactions.html#example-conditional-create-patch-on-same-resource I am aware that this might be specific to this fhir implementation but was wonderning if we could achieve the same goal in some ways in medplum