I'm tried to fatch my api data from backend by using axios. I'm getting an error, like this:

POST http://localhost:3000/undefined/post 404 (Not Found)

API routes like this:

// route middleware

app.use("/api", portRoutes);



// passing on controllers

router.post("/post", create);



// rest of code will have in controller folder

Now I have tried to work in frontend

I have tried by this way:

.env file

REACT_APP_API = http://localhost:8000/api

I dont know why does not access my server side links

handleSubmit function

const handleSubmit = (e) => {

    e.preventDefault();



    // access data from backend

    axios

      .post(`${process.env.REACT_APP_API}/post`, { title, content, user })

      .then((response) => {

        console.log(response);

        setState({ ...state, title: "", content: "", user: "" });

        alert(`Post Title ${response.data.title} is created`);

      })

      .catch((error) => {

        console.log(error.response);

        alert(error.response.data.error);

      });

  };

I'm sure my api is ok, I have checked my api with postman software.