What can be the Supporting Document for GSTIN Cancellation in the response of Form GST REG-03 ?

Dear Experts,

I am a Composite taxpayer under GST and no return is pending. My annual turnover is below the GST threshold limit i.e. Rs. 40 lakhs every year. That’s why I cancelled my GST registration 2 months ago under the reason for cancellation ‘Ceased to be liable to pay tax’. I have received Form GST REG-03 asking for Supporting Document to upload. What document can I upload to prove the fact that my annual turnover is below the GST threshold limit i.e. Rs. 40 lakhs every year.

Thanks in advance!