Dropbox eligibility for H1B - Over 2 years?

Hi ,

My previous h1b petition was extended from onsite and had the validity till April 2019 but the visa was not stamped on the passport as I was at onsite for this extension. But my passport visa image had expired on 2017 .

Am I eligible for drop box option for current extension stamping ?

No, you are not as your visa expired more than 2 years ago. It has to be under 1 year. But, for now until march 31, they have given extension for it to be under 2 years. Your expired in 2017, so it is way far and cannot use it.