How can I add a function to the class so that I can use "this."?

Question

JavaScript

I need to add a file with my functions to class bot: and call them with: 1) The bot is a 100% class 2) It has functions already written by the creators of discord (which are in [[Prototype]]) Maybe you can just put them in a regular prototype without these brackets or is there any way to fit them into an existing one?
const bot = new Discord.Client(config.cfg);
bot.funcname(args);

Answer 1

Normally:

Discord.Client.prototype.funcname = function(arg) { ...};