How to create a signature for bingx api in node js

Question

I want to generate a signature for Bingx website Api
Here's my code:

const Base64 = require('crypto-js/enc-base64');
const hmacSHA256  = require('crypto-js/hmac-sha256');

let originString = 'POST/api/v1/user/getBalanceapiKey=my_api_key' + '&currency=USDT&timestamp=' + Date.now();
let signature = hmacSHA256(originString, my_secret_key);
signature = Base64.stringify(signature);
signature = encodeURIComponent(signature);

I send the signature to the api But I get this error "signature not match"

Here's the bingx api authentication documentation: link1 and link2