感謝回答！
我的情況是2020年2月我已經繳費了，但是因為中美斷航，父母沒有過來。最近父母重新在廣州麵試才過來的。我的問題是還需要重新繳費嗎？我查了一下，他麽的IOE number還是沒有變的，所以我assume他們不需要繼續繳費了，但是向和老師confirm一下，謝謝！
-It seems you paid the visa application fee and the other fee related to the immigrant visa application, not the immigrant fee which is additional fee not related to the visa application. Immigrant fee only can be paid after they got the immigtrant visa. They need to pay this fee after they got the immigrant visa before thye enter US or after they enter US using the immigrant visa. Otherwise, they will not receive the plastic green card. Read this link carefully for the immigrant fee and how to pay it:
USCIS - Immigrant Fee - USCIS Immigrant Fee
