Why does my usdt prompt an address error when I want to transfer to a bitcoin address?

The bitcoin-based USDT (issued under the Omni protocol) and ethereum-based USDT (issued under the erc-20 protocol) cannot transfer to each other.

When transferring USDT, you can tell whether the USDTs are based on the same protocol by their address starting numbers: the USDT issued under Omni protocol starts with "1", and the USDT issued under erc-20 protocol starts with "0x".