After you've logged into the Mobile App, click on the "More" menu option in the bottom right corner.
After the More menu loads, scroll down and under "Additional Services" click the "Update Your Contact Information" menu option. Please note: your menu options may differ from the screenshot above.
You have the option to update your address, email address, and phone numbers here. Please remember that you cannot provide a P.O. Box for an address in online banking.