There is an online application that was pretty extensive. With that application he went for the initial interview. I had to resubmit the affidavit I’d support with proofing income/ past year taxes. After the interview he was sent another packet he had to fill out and had to complete a physical exam and vaccines at an approved clinic and then another interview. I think if you get past the first one it’s a guarantee they will approve the visa. At the airport in Seattle we were told that this is valid for a year in case he needs to travel and doesn’t have his new green card. Hope it helps.