This is the address: 13U4KkfPRUDKKr4yEUshx8rB1bM9MJbqnn
Until now, there is no recorded transaction in that BTC address. It is still empty.
Are you sure he successfully made the transaction? And the wallet address of the receiver is BTC not BCH right?
Is this blockchain wallet address, isn't this?
It means that your transaction is not confirmed, I think if this is not confirmed, he can cancel it. but, better to contact the support at first.
If it is said
pending , it is also probably about the transaction fee that is too low and he needs to increase the fee, see on details, and of course, ensure that you get the proof of the transaction. Ask the sender about the transaction and the fee.