ERROR: Parsing error: The keyword 'const' is reserved

[sugacoated]

In my main.js file,

// References to DOM Elements
const prevBtn = document.querySelector("#prev-btn");
const nextBtn = document.querySelector("#next-btn");
const book = document.querySelector("#book");

const paper1 = document.querySelector("#p1");
const paper2 = document.querySelector("#p2");
const paper3 = document.querySelector("#p3");

I am a beginner in coding and just want to try out a coding tutorial from youtube on how to code a flip book with js, css and html. However, while all my other files are working fine, my main.js file coding above seem to have a bug within. I have proofread my material and still don't know what to do about it. Please help :((((