How to update either, and what we do to make sure it's really you.
You can update your email and password at any time from the app.
Open Profile → Settings → Password. Enter your current password and pick a new one. The new password is checked against minimum-length and basic strength rules.
A password change doesn't sign you out of other devices automatically. If you suspect someone else has access to your account, change the password and then sign out from any other devices you don't recognise.
If you've forgotten your current password, use Forgot password? on the login screen instead — we'll send you a reset link by email.
Open Profile → Settings → Email. Enter the new email address and your current password. We'll send a verification link to the new email — until you click it, the old email stays active. This protects you in case the new email is wrong or compromised.
Once you click the verification link, the new email is live. Sign-in works with the new address from that point.
Change your password right away (if you can still get in). Then change your email to one you control. If you can't sign in at all, contact support — we can verify identity through other means and recover the account.
If you signed up with Apple or Google, the email is taken from there. To switch, you can connect a password to your Account from Settings, then change the email like above. After that, you can use either method to sign in.