Changenow is an instant exchange, if you want to exchange any coin and you want to make use of instant exchange service, the instant exchange will provide you an address, an address you will send the coin you want to trade, the address belongs to the instant exchange and once you send the coin to the address, they can decide to exchange the coin for you or seize your coin and demand for KYC if the coin is tainted or linked to illegal transaction.

If.using other instant exchanges, you may have the same experience. The best to have the full control over your asset is to use a decentralized exchanges like https://localcryptos.com/, https://hodlhodl.com/ which are P2P exchanges. Or go forlre decentralized one like https://bisq.network/ which is also p2p.