@Jessa ***
I re-read my FAQ, your question wasn't on the FAQ, so I added it:
K. WILL THE 60 DAY EXTENSION OF STAY BASED ON UNABLE TO TRAVEL DUE TO COVID-19 BE ADDED ON TO MY EXISTING EXTENSION OF STAY?
If you are getting your first extension of stay, the extension of stay will being on the date you apply. FOR MOST IMMIGRATION OFFICES, if you are applying for another extension of stay based on unable to travel due to COVID-19, the time will be added on to your existing stamp.