That's not how it works. When a bank makes a loan, the customer will use it to buy something (say, a house), and probably the money will be put in a different b

That's not how it works. When a bank makes a loan, the customer will use it to buy something (say, a house), and probably the money will be put in a different bank. So the money definitely needs to be there, to pay the other bank. There's a deposit in the other bank, along with the payment. Both of which are "money." So, a bank can create money from thin air by making a loan, but typically not for themselves. It happens in a different bank.