See the EWS certificate when asked is for the session when you are applying or its consecutive year. Now as your interview needs to have you the EWS certificate of the Financial year 2020-21, then you have to submit as it is applicable for the time period when you are applying for the examination. So you need to have that certificate else it may not be considered (for 2021-22 certificate, there are high chance that it wouldn't be considered).

To know more about the UPSC CMS visit the link below:

https://competition.careers360.com/exams/upsc-cms

I hope this answer helps. All the very best for your future endeavors!