ERC20 tokens are digital assets that exist on the Ethereum blockchain. They do not have their own independent blockchain. In order to send tokens such as USDT, WBTC, LINK, DAI, UNI, MKR, BAT, and any of the hundreds of other ERC20 tokens, you must pay an ETH fee for the transaction to be confirmed on the Ethereum blockchain. So before you buy or deposit any ERC20 tokens to your Ballet wallet, make sure that you have enough ETH on the wallet for the transaction fee that you will need to pay later when you want to send the tokens.
Why do I need to have ETH on my wallet in order to send ERC20 tokens?
Ballet Support