Only parse JSON if content length is not 0

src/static/js/helper.js

 async function fetchAPI(endpoint, options) {
     const res = await fetch(endpoint, options);
-    const data = await res.json();
+    const contentType = res.headers.get('content-length');
+    let data
+    if (!contentType.includes("0")) {
+        data = await res.json();
+    }
     if (res.ok) {
         return data;
     }