Besides managing your personal profile in Backlog, you can easily manage your login at your Nulab Apps account. In your Nulab Apps account, you can change your email or password to make your account updated and more secure.
Guide
Go to your personal icon > Personal Settings > Edit Nulab Account
In your Nulab Apps My Profile Page, in the Account page, you can easily update or change your email address.
For changing the password, you can go to Security tab and under password page, select Change Password. It will redirect you to a page to key in your current password and new password and select Update to apply the changes.
Tips: you may consider changing your password at a certain period to ensure their ongoing effectiveness. Try to avoid incorporate with your personal information.