TRX wallet does not support the function to add/hide tokens manually. After a token is successfully sent to TRX wallet, it will be automatically displayed on the asset page.
If you want to transfer USDT, NFT, BTT, etc. tokens to TRX Wallet, you can use the TRX wallet address as the receiving address. TRX wallet can be used to receive TRX, TRC10 and TRC20 type tokens.