A person contacted me on Facebook offering to purchase my digital artwork as NFTs. Though I proposed using Opensea platform for the transaction, he insisted on using this NFT Tradeplace instead, and claiming that this is the platform he trusted and has always been using. So I created an account on it and uploaded my artwork, then I was required to deposit 0.11ETH to the account through a wallet address as instructed by the live support of the platform to pay for the gas fee. After that the buyer seemed to complete the purchase the my account balance on the platform did show the receipt of ETHs, however, when I tried to withdraw part of the ETHs, the live support asked me to deposit another 0.7ETH to their wallet address, despite the fact the remaining ETHs on my account is sufficient to pay for the withdrawal fee. This is very unreasonable and suspicious. It is a scam website that everyone should avoid.