update default value

frontend/src/views/YTViews.vue

@@ -144,7 +144,7 @@ async function ECPaySubmit() {
   let getLang = localStorage.getItem("lang");
 
   // 綠界顯示語言
-  if (getLang === "zh") {
+  if (!getLang || getLang === "zh") {
     lang.value = "ZH";
   } else {
     lang.value = "ENG";