Annual return 18 -19

Yes... You can file.
but it's not mandatory...

Filing of anual return gstr9 is optional upto turnover limit of rs 2 crore

As per Notification No. 47/2019 - Central Tax, dated 09th October 2019 read with Circular No. 124 - GST, dated 18th November 2019, Filing of GST Annual Return ( FORM GSTR-9 ) for FY 2017-18 & FY 2018-19 has been made "OPTIONAL" for taxpayers having aggregate turnover upto Rs. 2 crores. It shall be "deemed to be filed" on the "DUE DATE" if not filed by the taxpayer on account of it being optional for them.

Since your Annual Aggregate Turnover is less than Rs. 2 crores, you are not required to file FORM GSTR-9. Also note that in the Circular it was clearly mentioned that "No one will be allowed to file Annual Return after the due date [ Due Date : 31st December 2020 ]."

Annual return optional , below 2 Crore !

Is it optional for 2019-20 too

Due date of submitting annual return for 2018-19 has been extended upto 31st March,2021.