Fixed query build error & added api to landingpage

js/api.js

@@ -1,4 +1,4 @@
-const prefix = "";
+const prefix = document.getElementsByTagName("base")[0].href;
 async function unknownResponse(resp) {
     let json = await resp.json();
     try {
@@ -18,10 +18,10 @@ function buildQuery(options) {
             else if (element[1] instanceof Array) {
                 element[1] = JSON.stringify(element[1]);
             }
-            query.push(`${element[0]}&${element[1]}`);
+            query.push(`${element[0]}=${element[1]}`);
         }
     });
-    return query.join("=");
+    return query.join("&");
 }
 async function login(username, password) {
     let result = await fetch(`${prefix}/api/login`, {