How to recover and add a notification email for Apple ID?

While i was trying to change my Apple ID email, it had told me i couldn’t use the same email as my notification email. So what i did was click the X on the notification email and i assume it deleted it and now that i try to go and put a new one i can’t find the tab that says notification email anymore like before. I don’t know how to get it back or just add a new notification email since it doesn’t show up. Please help!!