If you want to connect to chat as a user, you need a user to go through the OAuth process to grant you a token that lets you log in to chat as them.
There is no way to avoid that. Discord has specific ‘bot’ accounts that you connect as, on Twitch though all bots are actual user accounts on Twitch, so if you want your bot to be called ‘MyBot’, you would need to create that account on Twitch and go through the OAuth process of your app while logged into Twitch as that.
If you only need to read chat you can connect with the username justinfan1234, and an empty string "" as a password, so you wont need any OAuth token for that, but because it’s not a user you can’t send any messages.