Unauthorized error in http call

I am using below code in 19c (19.10.0.0.0) to call a rest api. I am getting 401 unauthorized error however same token is working fine in postman. Please help me to find out what is the mistake in my call to api.

DECLARE

req   UTL_HTTP.REQ;

  resp  UTL_HTTP.RESP;

  name  VARCHAR2(256);

  value VARCHAR2(1024);

  buffer varchar2(4000);

  content varchar2(4000) := '[

  {

    "plantID": "ITM",

    "skuCode": "RB.0FU.07G10C.01.05",

    "skuDesc": "FU UR LID - WHITE",

    "suppSKUCode": "",

    "suppSKUDesc": "",

    "prodClassCode": "Bathware",

    "prodClassCode1": "Urinal Lid",

    "pickStrategy": "FIFO",

    "uom": "EA",

    "active": true,

    "packageType": "pkg01",

    "eachLength": 0,

    "eachWidth": 0,

    "eachHeigth": 0,

    "caseLength": 0,

    "caseWidth": 0,

    "caseHeigth": 0,

    "palletLength": 0,

    "palletWidth": 0,

    "palletHeigth": 0,

    "palletQty": 0,

    "eachPerLayer": 0,

    "layersPerPallet": 0,

    "conversionFactor": 0,

    "varUOMDesc": "EA",