You've already added your MyHeritage DNA test information to your own profile. If you took another DNA test, you can add that new test information by clicking on 'DNA test information' on the drop-down list under 'Add' at the top right of your profile. Scroll down the page to the section headed 'Add new test information'. Because of the European Union's GDPR we can no longer add DNA test information to profiles for other living people. You need to invite your father to join WikiTree by entering his e-mail address on his 'edit' page, just below the entry for 'gender'. Once he joins he can add his own test.