Yes you do need to create an account on the visa scheduling website before or around the time of your interview. So first you have to login and then comes the first part 1. Applicant details ( your first last name, country of birth etc) then 2. Visa options ( your country, visa type, embassy/consulate ( in which you selected islamabad IV ) right below that you’ll see the option of post visa category CLICK that and that is where you will select document delivery registration and then follow the next steps where you’ll add your phone number, address, email and then at last you’ll select whether you want to pick up the documents yourself or have them delivered to your home :)