All transactions that are published onto the public Ethereum blockchain will require a transaction fee, otherwise known as a gas fee. This is a small amount of ETH that must be sent alongside your Minds token payment in order for the transaction to be processed.
Gas is measured in wei, where 1 ETH = 1,000,000,000,000,000,000 wei, or 1 Gwei (Giga wei) = 0.000000001 ETH. The daily price of gas can be tracked at https://etherscan.io/gastracker.