If it’s sending messages as your broadcaster username it’s because the bot is connecting to chat with your username and OAuth token. If you want the bot to use it’s own username, you need to have it connect using that username/OAuth token instead.
You need to use the bot account to generate the token. So if you’re using a site like that, first log into Twitch as your bot account, then go there and generate the token.
Thanks, I wasn’t sure since IRC lets you set nicknames I would have thought that it would send via the nickname specified bound to the broadcaster user somehow