GST Refund for the FY 18-19 can be filed now?

We have to file ITC Refund application. For the FY 18-19 due date completed. We can file only for the FY 2019-20, FY 2018-19 should be filed nil return.

But the person to whom we send the data asking data for the FY 2018-19 to file the return.

He says the GST accept the data for the FY 2018-19 also.

Please advice can we file GST Refund on inverted tax structure for the FY 2018-19 now