I'm creating a discord bot, and trying to host it in Heroku. After installing all dependencies I tried to test before deploying but the following error appears:

```none
nicolasperez@nicolasperez-Nitro-AN515-51:~/Documents/DMGBOT$ heroku local
3:00:24 AM worker.1 |  > dmgbot@1.0.0 start /home/nicolasperez/Documents/DMGBOT
3:00:24 AM worker.1 |  > node bot.js
3:00:25 AM worker.1 |  (node:7624) UnhandledPromiseRejectionWarning: Error: An invalid token was provided.
3:00:25 AM worker.1 |      at Promise (/home/nicolasperez/Documents/DMGBOT/node_modules/discord.js/src/client/rest/RESTMethods.js:33:44)
3:00:25 AM worker.1 |      at new Promise (<anonymous>)
3:00:25 AM worker.1 |      at RESTMethods.login (/home/nicolasperez/Documents/DMGBOT/node_modules/discord.js/src/client/rest/RESTMethods.js:32:12)
3:00:25 AM worker.1 |      at Client.login (/home/nicolasperez/Documents/DMGBOT/node_modules/discord.js/src/client/Client.js:277:30)
3:00:25 AM worker.1 |      at Object.<anonymous> (/home/nicolasperez/Documents/DMGBOT/bot.js:194:5)
3:00:25 AM worker.1 |      at Module._compile (module.js:652:30)
3:00:25 AM worker.1 |      at Object.Module._extensions..js (module.js:663:10)
3:00:25 AM worker.1 |      at Module.load (module.js:565:32)
3:00:25 AM worker.1 |      at tryModuleLoad (module.js:505:12)
3:00:25 AM worker.1 |      at Function.Module._load (module.js:497:3)
3:00:25 AM worker.1 |      at Function.Module.runMain (module.js:693:10)
3:00:25 AM worker.1 |      at startup (bootstrap_node.js:188:16)
3:00:25 AM worker.1 |      at bootstrap_node.js:609:3
3:00:25 AM worker.1 |  (node:7624) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
3:00:25 AM worker.1 |  (node:7624) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
[DONE] Killing all processes with signal  SIGINT
3:00:25 AM worker.1 Exited Successfully

```

I don't understand why this happens, as I have already set the config variables in the app settings in Heroku.

Here is the code for the bot: the important line is the last one, where the bot tries to log in with a valid token.

```
const botconfig = require("./botconfig.json");
const Discord = require("discord.js");
const Gamedig = require('gamedig');
const bot = new Discord.Client({disableEveryone: true});

bot.on("ready", async message => {...});

bot.on("message", async message => {...});

bot.login(process.env.BOT_TOKEN);

```

I have tried resetting the bot token numerous times, surrounding them with quotation marks, and including a `.json` with the token, but nothing has worked so far.  

Why don't the config vars work knowing that they're set to a valid discord bot token? What other solutions can help my bot work without issues?