As per sub rule (2) of Rule (5) of the CGST Rules 2017, persons who are paying tax under section 10 [ Composition Scheme ] are not required to make a Fresh intimation every year to opt in the Scheme.
So no fresh intimation ( in FORM GST CMP-02 ) is required to opt for Composition Scheme for FY 2019-20 if you were registered as a Composite Dealer in FY 2018-19.