// Pastikan payload minimal ini benar di cek_nik.php
$payload = [
    "resourceType" => "Patient",
    "meta" => ["profile" => ["https://fhir.kemkes.go.id/r4/StructureDefinition/Patient"]],
    "identifier" => [[
        "use" => "official",
        "system" => "https://fhir.kemkes.go.id/id/nik",
        "value" => $nik
    ]],
    "active" => true,
    "name" => [["use" => "official", "text" => "REZA DICKY KURNIAWAN"]], // Nama Testing
    "gender" => "male",
    "birthDate" => "1995-03-29", // Format wajib YYYY-MM-DD
    "telecom" => [[
        "system" => "phone",
        "value" => "085800000825",
        "use" => "mobile"
    ]],
    "contact" => [[
        "name" => ["text" => "IBU KANDUNG REZA"]
    ]]
];