GSTR 3B after registration cancellation

I discontinued my business from 25th April and now want to apply for cancellation of GST return. However, I am unable to file GSTR 3B for June quarter (quarterly frequency) as the same has not yet been activated on GST portal. Will I be able to file GSTR 3B after application of cancellation or should I first file GSTR 3B and then apply for cancellation in July (Ideally, we should make application within 30 days of discontinuation). 

Anyone on this?