Your verified email address is required to link a bank account to your OK app and to freeze your OK app if you lose your mobile phone.
You can change or fill in your email address in your settings. To get here, click on the gear icon from the overview screen in the top right corner. Under the header 'Me’ you will find, among others 'E-mail address'. Click to fill in or change your mobile number. Then click 'Save' in the upper right corner.
You will then receive a new confirmation email that you must confirm. Email addresses that will not be confirmed within 5 minutes will be deleted. No worries, you can do it again.
[More about what to do if you do not receive a confirmation email]