discord.js activity code example
Example 1: discord.js bot activity
bot.user.setActivity('some activity', { type: 'WATCHING' }) // STREAMING, WATCHING, CUSTOM_STATUS, PLAYING, COMPETING
.then(presence => console.log(`Activity set to ${presence.activities[0].name}`))
.catch(console.error);
Example 2: discord bot playing game
client.user.setActivity("what the bot is playing");
Example 3: discord js channel send
const user = <client>.users.cache.get('<id>');
user.send('<content>');
Example 4: discord js channel send
const channel = <client>.channels.cache.get('<id>');
channel.send('<content>');