H4 visa expired and applying for new one- What is the process?

My dependents H4 visa was expired and I am looking for the process to apply again to bring them to US. Are they eligible for Dropbox?

First time/Initially they got H4 visa for 1 year along with me (H1) but they didn’t travel with me to US due to some personal reasons… Now the VISA validity period is expired and I am planing to bring them to US. My extension and stamping done.

If their H4 visa has expired within the past 1 year, you may be eligible and there are couple of other questions they ask as you fill up the DS 160. Once you fill them up you would be told if you are eligible for drop box or you will have to do an interview.