When creating your Arke account, or changing the email address for your account, you will be asked to verify your email address.
The change your email address screen
To confirm that you own the email address you sign up with, we'll send a verification code to the email address you give us which you enter during the sign-up process on the Arke website.
An example verification code sent via email
You can enter this code into the into the 'Verification code' field:
Next, reenter your password in the password field and click 'Verify email address':
Did you not receive the verification email? Check this article