A valid passport, identity document or residence permit which is machine readable
The NO_NAME app. Any phone will do, in other words you could use a shared phone or borrow a phone to execute the enrollment.
Such doucments will contain this symbol on the binder front (for passports) or clearly visible on the document.
The app should prompt you to validate the following text for your safty "prelatising-humdrum" to ensure that you are identifying toward the correct actor and in the correct context.