Request authorization error in Spotify API

The weirdest thing is happening to my react app. I have moved the Client Id and Client Secret into the environment variables and am loading them into this file using dotenv to create an authorization request:

// Inject environment variables
import dotenv from 'dotenv';
dotenv.config();

const clientID = process.env.CLIENT_ID;
const clientSecret = process.env.CLIENT_SECRET;

// Request authorization
const authOptions = {
  url: "https://accounts.spotify.com/api/token",
  headers: {
    "Authorization":
      "Basic " +
      new Buffer.from(clientID + ":" + clientSecret).toString("base64"),
    "Content-Type": "application/x-www-form-urlencoded",
  },
  form: {
    grant_type: "client_credentials",
  },
  json: true,
};

export default authOptions;

But I’m getting a Failed to load resource: the server responded with a status of 400 () error:

{ error: "invalid_client", error_description: "Invalid client" }

The weird part is that if hard code the client id and secret, it works flawlessly.

I have even printed the environment variables in the console and am getting the correct values but the moment I use them in the authorization header it stops working.

Is there any way to fix this?