Sir,
According to Section 31 (d) & (e) of CGST Act, 2017
"a registered person shall, on receipt of advance payment with respect to any supply of goods or services or both, issue a receipt voucher or any other document, containing such particulars as may be prescribed, evidencing receipt of such payment.
where, on receipt of advance payment with respect to any supply of goods or services or both the registered person issues a receipt voucher, but subsequently no supply is made and no tax invoice is issued in pursuance thereof, the said registered person may issue to the person who had made the payment, a refund voucher against such payment."
Rule 50 of CGST Rules, 2017 prescribes the details to be contained in receipt voucher.