fix paths

src/api/backend.ts

@@ -55,8 +55,8 @@ const getHeaders = (auth?: boolean): Headers => {
 
 const fillUrlParams = (apiPath: APIPath, params: API["urlParams"] = {}): string => {
   const path = apiPath
-    .split("/")
-    .filter(Boolean)
+    .split("/") // ["", jobads", ":id"]
+    .filter(Boolean) // [jobads", ":id"]
     .map((urlComponent) => {
       // fill in each placeholder component like ':id' with value from params
       if (urlComponent.startsWith(":")) {
@@ -66,9 +66,9 @@ const fillUrlParams = (apiPath: APIPath, params: API["urlParams"] = {}): string
       }
       return urlComponent;
     })
-    .join("/");
-  // code above strips leading '/' from path
-  return `/${path}`;
+    .join("/"); // "jobads/:id"
+  // code above strips leading and trailing '/' from path
+  return `/${path}/`;
 };
 
 const callBackendAPI = async <RequestType, ResponseType>(