Get raw request body in custom controller

I am trying to do this in Strapi version 4.12.1, in a custom controller in my plugin, but ctx.request.body[Symbol.for("unparsedBody")]; returns undefined. Here is my function so far:

'use strict';

const crypto = require("crypto");

module.exports = ({ strapi }) => ({
  async handle(ctx) {
    const secretKey = process.env.SHOPIFY_API_KEY;
    const hmac = ctx.request.get('x-shopify-hmac-sha256');
    const rawBody = ctx.request.body[Symbol.for("unparsedBody")];
    console.log("RAW BODY:", rawBody); // prints RAW BODY: undefined
}});

I have tried to google it, and searched the forum, but I can not find a way to get this to work. Can anyone help?