NVC has sent a letter for the interview appointment for my dad’s DS-260 (immigration visa) however I can’t find how to register the appointment with VAC. On the https://www.usvisascheduling.com/en-US/ website, there’s no Schedule appointment button. I created his account today but we got the letter two weeks ago. I have been trying to figure out what to do, nobody answers phones and customer support is beyond unhelpful.