The value field in our callback (or IPN) is the amount paid as an integer. This makes exact calculations easier on some platforms.
Stablecoins are a special case. For tokens such as USDT and USDC, value is rounded to cents (two decimals), so you must divide it by 100 to get the amount paid.
We advise you to use the value_coin field instead. It's always in whole coins and keeps every decimal, which matters if your customer sends an amount with more than two decimals.