Log into your Roku account at https://my.roku.com using your old email address (it's just a login name at this point). Once logged in you can change your email address. This will update your login name and the email address on your account.
I don't recall Roku taking a phone number.
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X