Can a revised return be filed after I get the assessment order

Hi,

 I filed my return on 21st Dec 2020 for AY 20-21 and that duly got assessed and I got a assessment order with 'No payment due'. But recently I got a notification from e-campaign compliance and notified that I missed to show some amount of FD interests in my ITR. What should I do ? I paid the extra tax right away. But should I submit a revised return ? Please note that I already got a assessment order from income tax with 'No payment due' with my original return on Dec 2020 itself.

Please advice.