discord bot create remove text channel
You can delete a channel with Channel.delete(). If you'd like to delete the channel a command was sent in, you can do something like this:
message.channel.delete.catch(console.error);
To delete all channels, you can use Collection.each()
// iterate a function through all channels in a guild
message.guild.channels.cache.each((channel) =>
channel.delete().catch(console.error));