When your TRX balance is 0, you can still obtain TRX for network fees by swapping from USDT and sending to your wallet.
Common intent behind “buy online TRX” is speed: users want TRX delivered quickly to a wallet address with TRC20 clarity.
If you are swapping from USDT, confirm the destination network matches your wallet. Mistakes can lead to loss.
For fee funding when TRX is 0, a small swap can provide the TRX needed to complete transactions.
Before you send or store TRX, back up wallet recovery info and verify addresses character-by-character.