How to use axios interceptor in JavaScript

axios.js

import Axios from "axios";

const axios = Axios.create({
  baseURL: process.env.SERVER_BASE_URL,
  
  headers: {
    "Content-Type": "application/json",
  },
});

axios.interceptors.response.use(
  (response) => {
    if(response.data?.message) alert (response.data.message);
    
    return response.data;
  },
  (error) => {
    alert(error?.response?.data?.error || "Could not connect to server");
    
    return Promise.reject(error?.response?.data);
  }
);

axios.interceptors.request.use((config) => {
  const token = localStorage.getItem("token");

  if (token) {
    config.headers.Authorization = token ? `Bearer ${token}` : "";
  }

  return config;
});

export default axios;