How do you buy with phantom?

Could you please elaborate on the process of purchasing items using Phantom? I'm curious to know how it works. Could you provide a step-by-step guide on how to initiate a purchase transaction with Phantom? Additionally, are there any specific requirements or considerations that need to be taken into account when using Phantom for purchases? I would also appreciate any insights into the security and privacy aspects of this payment method. Thank you for your assistance.