JavaScript Fetch API Error When Sending GET Request Using URL Parameter

I’m trying to send a GET request to an API to fetch courses based on a category specified in the URL. I’m using the fetch API in JavaScript to do this, but I’m encountering an error. The code I’m using is as follows:

// Function for getting key from URL

const getUrlParams = (key) => {
  const urlParams = new URLSearchParams(location.search);
  return urlParams.get(key);
};

// Function to fetch courses based on category

  const getAndShowCategoryCourses = async () => {
    let categoryName = getUrlParams("cat");

    const res = await fetch(
     `http://localhost:4000/v1/courses/category/${categoryName}`
   );
    const courses = await res.json();
    return courses;
   };

Expected Behavior: The function should fetch and log the list of courses based on the cat parameter from the URL.

Actual Behavior: Instead of fetching the courses, I get the error:

[ “message”: “this route is protected and you can’t have access to it.”]

Browser/Environment: I’m testing this on Chrome and the backend tech are node and MongoDB.

Backend Details: The API is running on a local server at http://localhost:4000/v1/courses/category/:categoryName.

Steps Taken:
I verified that the cat parameter is correctly retrieved using getUrlParams,
and when I’m testing this API using postman with this API (http://localhost:4000/v1/courses/category/backend) and it gives me the same error:

[ “message”: “this route is protected and you can’t have access to it.”]