Написал в службу поддержки и прислали мне вот это.
Thank you for writing to the U.S. Visa Service Desk.
We understand that you would like to clarify regarding your visa application steps.
Regarding this concern, if you can answer the questions at step 7 in such a way that you confirmed that you qualify for visa renewal without a consular interview, you may apply for a visa through Interview Waiver Service, and you will receive a Interview Waiver submission letter containing a document checklist at the last step.
Kindly review the qualifications and process for Interview Waiver Submission at http://www.ustraveldocs.com/vn/vn-niv-visarenew.asp
NOTE: If you are applying for a B1/B2, C1/D or F, M, J visa, please ensure you read and answer all the Interview Waiver questions carefully. Only answer Yes to the questions if you fully comply with all points listed under every question. In case you do not qualify for Interview Waiver and have wrongfully responded to any question, you will be requested to schedule an appointment for an interview.
We hope this information is helpful to you.
Please send us your feedback and suggestions through the link below:
https://www.surveymonkey.com/s/gss_vietnam