H4 Visa Stamping without H1B applicant

Hi All,

Please help me on my question:

Im in USA on H1B with my wife and 2 yr old kid(both H4). Visa stamp for all 3 of us expired in June 2019. But we got our H1B and H4 visa approval until June 2022.

Only my wife and kid will be travelling to India in Feb 2021. As per the new update, the dropbox facility has been extended untill March 31, 2021 and the duration from last visa expiry is 24 months.
So we do qualify for dropbox.

But, since only my wife and kid will be travelling and I will not, are they still eligible for dropbox or is it mandatory for me also to go for stamping.