A bot can’t do this, simply put
The short answer is you don’t
The long answer,
Is you build a portal (aka Webpage), and ask each subscriber to login with the user_read scope (or OIDC flows) that will grant you access to read the Twitch listed email address for the user.
But if you are doing that, you should just give users a field to input their email into. So you ask the user to provide an email to be contact on instead.