The recipient’s address has not yet been activated on TRON. Inactive addresses can still receive TRX, USDT, and other tokens, so there is no need to worry.
Sending TRX to an inactive address automatically activates it. The TRON network charges the sender an additional 1 TRX account activation fee.
If you want to send your entire TRX balance, leave at least 1 TRX in your wallet and ensure you have enough bandwidth for the transfer.
Learn more: How to activate your TRX wallet