 Use Amazon's app and website. They do not ask for payment over the phone or over email. They will never ask for that. So it's always through the website. Be wary of any false urgency. This is a tactic scammers always use. They try to create a sense of urgency. Hey, we've got this thing to deliver to you, but we can't deliver it. We can't finish it because we need this final payment. Don't do it.