It's a good idea to attach an email to your account and to keep that email address up to date. Your account email can work as your username, and adding an email will also let you reset your password whenever you need to.
Editing your account email
Step 1: Click the Profile Icon in the upper right corner of your dashboard.
Step 2: Click on Settings.
Step 3: From your Settings page, delete your old email address and enter the new one.
Step 4: Click Update to save.