ASV stands for Amazon Shopping Voucher, which is similar to a Flipkart voucher. The major difference between Amazon Pay and Amazon Shopping Voucher is that Amazon Pay can be used as cash for paying bills and making purchases, whereas Amazon Shopping Voucher can only be used for shopping.
If you have any Axis Cards, such as debit or credit cards, you can purchase the Amazon Shopping Voucher from this website. It offers a flat 2% discount, as well as additional Reward Points.
grabdeals.axisbank.com
Alternatively, if you have HDFC Cards, you can buy the voucher from this website, which provides a flat 5% cashback and, in some cases, cashback along with reward points.