Have your CORSIA emission report for 2019 verified: 

Starting 01. January 2019, all aeroplane operators are required to monitor CO2 emissions from international flights.
We recommend to reach out to the State that administers your airline (usually the State which is mentioned in the ICAO designator or AOC) and inquire about the CORSIA annual emission report template and submission deadlines for this year. 

Now in 2020 operators have to submit a verified emission report for 2019 to the national State Authority to which they are attributed. Prior to to the submission of the report, the collected flight and emissions data has to be verified by an accredited verification body.