Can chairman get an undertaking from lawyer

I'm the Chairman of the society and during last SGM society passed a resolution on that conveyance amount was 5.88 lakhs (excluding black money) but the total amount paid till now is 8.7 lakhs so society members are saying that either give receipts/voucher or all 3 committee members will pay equal amount to settle this dispute. Then corona happened and there was no SGM after that but we have found vouchers for all the amount. Now i have sold my flat but the buyer needs noc from society for home loan but secretary is saying take an undertaking from lawyer that wherever I'll go, I'm the sole responsible person to clarify this matter.