我有一個(gè) Angular 項(xiàng)目，我必須在其中實(shí)現(xiàn)數(shù)據(jù)傳輸支付。但我無法生成付款標(biāo)志。我正在按照此鏈接上給出的過程（在此處輸入鏈接描述）生成符號(hào)。但我無法實(shí)現(xiàn)它。我正在使用角度庫(kù) crypto-js 生成 HMAC-SHA-256 簽名字符串。這是我的javascript代碼。const merchantId = 'xxxxxxx';const refNo = '1234567890';const amount = 0;const currency = 'CHF';const theme = 'DT2015';const paymentmethod = 'VIS';const stringSs = merchantId+amount+currency+refNo;const base = 16;// My Hmac Keyconst s = 'fa3d0ea1772cf21e53158283e4f123ebf1eb1ccfb15619e2fc91ee6860a2e5e48409e902b610ce5dc6f7f77fab8affb60d69b2a7aa9acf56723d868d36ab3f32';// Step 1: Code to generate hex to byte of hmac keyconst a = s.replace(/../g, '$&_').slice (0, -1).split ('_').map ((x) => parseInt (x, base));//  Step 3: Sign the string with HMAC-SHA-256 together with your HMAC keyconst signedString = HmacSHA256(a, stringSs);// Step 4: Translate the signature from byte to hex formatconst signString = enc.Hex.stringify(signedString);您能幫我解決這個(gè)問題，以建議我做錯(cuò)了什么或可以通過什么方式實(shí)現(xiàn)。