In order to change your phone number or email address, you need to be using the Hilton Honors Debit Card app.
Click on your initials in the top left of the app, then click on 'Details' just under your name. You can then update your home address, phone number and email address after some security checks.
If you're not able to update these, you should be directed to the Hilton Honors Debit Card Customer Support team.