By Notification Central No.64/2020 dt 31.08.2020, time to for filing FORM GSTR-4 for financial year 2019-2020 is extended to 31.10.2020.This is the annual return for Composition dealers which expired on 31.08.2020.
https://www.cbic.gov.in/resources//htdocs-cbec/gst/notfctn-64-central-tax-english-2020.pdf