We see that the payer has selected their preferred deposit currency and sent the requested amount of 0.01080852 BTC. The initial fixed rate has been respected and the deposit has been denominated to the expected 500 EUR (before fee). Please note, that had the payer deposited half of the requested amount in BTC, the fixed rate would still have been respected, however, the denominated amount would be 250 EUR in this case.
Fixed rate is available for the following cryptocurrencies: BTC, ETH, XRP, LTC, BCH, USDT