If you are making the application to have a client ID to make queries to the API, you can leave it under your account and just use the client ID during the bot’s queries. The bot can be a different account.
This is for web based applications, you can leave it as something like your twitch page just as a filler, you can change it later if needed. For a chat bot with no web interface it isn’t really needed.
You can make your own application to request a chat token as a specific user, or you can use something like: Twitch Chat Password Generator and use your bot credentials to get it’s “chat oauth” with scope=chat_login
The URL it just where the user would be redirected to after authentication. If you make a web app just to generate a chat_login oauth then where it redirects you to is trivial.