3. There should be a certain amount of native tokens on each chain in advance as the gas fee for receiving test tokens. If you have already received tokens other than the native token on a chain, you will not be able to repeatedly claim from the Zecrey faucet. For example, on Rinkeby, ETH is needed to claim the other nine test tokens. So do the other four networks, MATIC on Mumbai, ETH on Aurora testnet, AVAX on Avalanche testnet and BNB on BSC testnet.