Sending message to specific channel, not working - node.js

Question

Having trouble sending a bot message on a specific channel. I very simply want to have the bot send a message to #general when it activates, to let everyone know it's working again.
In the bot.on function, I've tried the classic client.channels.get().send(), but the error messages I'm getting show that it thinks client is undefined. (It says "cannot read property 'channels' of undefined")
bot.on('ready', client => {
console.log("MACsim online")
client.channels.get('#general').send("#here");
})
The bot crashes immediately, saying: Cannot read property 'channels' of undefined

Answer 1

The ready event doesn't pass any client parameter.
To get a channel by name use collection.find():
client.channels.find(channel => channel.name == "channel name here");
To get a channel by ID you can simply do collection.get("ID") because the channels are mapped by their IDs.
client.channels.get("channel_id");
Here is an example I made for you:
const Discord = require("discord.js");
const Client = new Discord.Client();
Client.on("ready", () => {
let Channel = Client.channels.find(channel => channel.name == "my_channel");
Channel.send("The bot is ready!");
});
Client.login("TOKEN");

Answer 2

You need to get the guild / server by ID, and then the channel by ID, so your code will be something like :
const discordjs = require("discord.js");
const client = new discordjs.Client();
bot.on('ready', client => {
console.log("MACsim online")
client.guilds.get("1836402401348").channels.get('199993777289').send("#here");
})
Edit : added client call

Answer 3

The ready event does not pass a parameter. To gain the bot's client, simply use the variable that you assigned when you created the client.
From your code, it looks like the bot variable, where you did const bot = new Discord.Client();.
From there, using the bot (which is the bot's client), you can access the channels property!