Peatio generates a single ETH wallet for every user.
For testing you can connect peatio to ethereum testnet like Rinkeby, Kovan, Ropsten or Goerli.
To get test coins in Rinkeby network do the following:
To get ETH in Kovan network you will need GitHub account. Go to https://gitter.im/kovan-testnet/faucet, sign in and post message with your ETH address. In few minutes you will get money automatically. Don't post too often or you can be banned.