221(g) after dropbox submission

Hi All,

 I had submitted my passport for H1B Visa stamping via dropbox facility and I got 221(g) blue slip asking me to attend interview. They have not requested for any specific documents, only the attend interview box is checked. My question is, do I have to go for finger printing on the first day and then attend the interview on the second day similar to regular visa interviews or can I walk in for the interview directly?