PowerBI NetSuite POST Rest API Create Client_Assertion token

Good Day,

With the help of Netsuite consultants, i manually coping the temp auth token key i can access Netsuite from API

I am trying to generate the authenticaion token, i was informed i need the assertion param value that postman uses as an example

1. The below is the javascript but how do i translate this to powerquery function?

pm.collectionVariables.set('companyId', pm.collectionVariables.get("NSCOMPID"));

var navigator = {}; // necessary as part of "eval" on jsrsasign lib
var window = {}; // necessary as part of "eval" on jsrsasign lib
eval(pm.globals.get("jsrsasign-js")); // grabbing jsrsasign lib, loaded in separate GET 

const cryptojs = require('crypto-js'); // using crypto js for base64 encoding

// Create JWT header
var jwtHeader = {
    alg: 'PS256', // Using PS256, which is one of the algorithms NetSuite supports for client credentials
    typ: 'JWT',
    kid: pm.collectionVariables.get("KID") // Certificate Id on the client credentials mapping
};

var stringifiedJwtHeader = JSON.stringify(jwtHeader);
console.log('jwtHeader: ' + stringifiedJwtHeader);
// Create JWT payload
var jwtPayload = {
    iss: pm.collectionVariables.get("CONSUMER_KEY"), // consumer key of integration record
    scope: ['restlets','rest_webservices'], // scopes specified on integration record
    iat: (new Date() / 1000),               // timestamp in seconds
    exp: (new Date() / 1000) + 3600,        // timestamp in seconds, 1 hour later, which is max for expiration
    aud: pm.collectionVariables.get("RESTLET_URL")
};

var stringifiedJwtPayload = JSON.stringify(jwtPayload);
console.log('jwtPayload: ' + stringifiedJwtPayload);
// The secret is the private key of the certificate loaded into the client credentials mapping in NetSuite
var secret = pm.collectionVariables.get("CERTIFICATE_PRIVATE_KEY");
console.log('secret: ' + secret);
var encodedSecret = cryptojs.enc.Base64.stringify(cryptojs.enc.Utf8.parse(secret)); // we need to base64 encode the key

// Sign the JWT with the PS256 algorithm (algorithm must match what is specified in JWT header).
// The JWT is signed using the jsrsasign lib (KJUR)
var signedJWT = KJUR.jws.JWS.sign('PS256',stringifiedJwtHeader,stringifiedJwtPayload,secret);

// The signed JWT is the client assertion (encoded JWT) that is used to retrieve an access token
pm.collectionVariables.set('clientAssertion', signedJWT);

2. Below is my WIP version but im missing the javascript library that postman uses and the KID Param values etc, 

let
    // Define your client ID and client secret
    clientId = "a0a...",
    clientSecret = "1b3c...",    
    // Construct the assertion payload
    assertionPayload = [
        iss = clientId,
        sub = clientId,
        aud = "https://xxx.suitetalk.api.netsuite.com", 
        exp = Number.ToText(Number.Round(DateTimeZone.FixedLocalNow() + #duration(0,0,1,0))),
        iat = Number.ToText(Number.Round(DateTimeZone.FixedLocalNow()))
    ],

    // Convert the assertion payload to JSON
    assertionPayloadJson = Json.FromValue(assertionPayload),
    // ConvertToBinary
    encodedPayload = Binary.ToText(assertionPayloadJson, BinaryEncoding.Base64),

    // Construct the assertion header
    assertionHeader = [
        alg = "MII...",
        typ = "JWT"
    ],

    // Convert the assertion header to JSON
    assertionHeaderJson = Json.FromValue(assertionHeader),    
    // Encode the header to base64    
    encodedHeader = Binary.ToText(assertionHeaderJson, BinaryEncoding.Base64),

    // Concatenate the encoded header, payload, and signature
    assertion = encodedHeader & "." & encodedPayload,

    // Sign the assertion using the client secret
    signedAssertion = assertion & "." & ""
in
    signedAssertion

Please Help, Any ideas or links of someone doing this before