Cable notification for H1B Renewal

Hello There,

 My H1B expires on 31st Aug'2020, I came to India in the month of March for some personal reason and stuck here because of on going COVID 19 issue.  My attorney said that they can initiate cable notification if I am not able to return to US before my H1B expires.

1. What is cable notification
2. Do I need to go to consulate for interview again or drop box can be used for renewal.