When I try to exchange cryptos, the exchange rate is not even close to accurate.
Trading function
It is probably because your order exceeds the liquidity in the BNB PRV pool. Liquidity pools over several coins have changed significantly in recent days as the development prepares to launch PDEX v3 at the end of the month.
https://we.incognito.org/t/introducing-the-new-pdex-pdex-v3/13026/3
The answer is literally in your screenshot:
There are only 208.8752 PRV (~$409) in the BNB liquidity pool. Yet you are attempting a cross-pool trade of 2.3060 BNB (~$1072). AMMs do not have CEX order books. The AMM tries to keep each LP pair balanced in value. If either of the pools are small, the slippage required to maintain a (somewhat) balanced LP will be significant.
Besides, he chose the wrong BNB (BEP20/BSC). He should have chosen BEP2 BNB for higher liquidity.