▶the USDT is going to be classified automatically ?
I understand your question, and this is exactly what I am explaining. Your USDT is already in your LBank account. If you want to transfer it to another LBank user, you can simply use Internal Transfer. You transfer USDT, and the recipient will receive USDT in their LBank account. The network you originally used to deposit the USDT into LBank does not affect this internal transfer. Just make sure you enter the correct recipient UID before confirming the transfer.
▶with internal transfer through UID, is it also needed entering which USDT network he is using ?
No, that won’t be necessary.
For an Internal Transfer, you do NOT need to select any blockchain network at all. Since both you and the recipient are LBank users, you only need to enter the recipient's correct LBank UID and transfer the USDT directly.