If you have an Alexa device, you can set it up so that it will purchase items when you ask it to. However, this gives anyone in your home, including guests, the power to buy something with your credit card easily. It’s more secure to enable a PIN that you also have to say along with your purchase. This is an option when you set up voice purchases in your account. It’s also best to make sure that no one is within earshot when you say your PIN to your device.