How would you describe the process of paying with WhiteBIT? Is it a straightforward and seamless experience, or does it require some additional steps or precautions? Are there any specific payment methods that are supported by WhiteBIT, or does it offer a wide range of options? Additionally, is there any information or requirements that a user needs to be aware of before making a payment through WhiteBIT? Finally, how does WhiteBIT ensure the security and safety of its payment system for both buyers and sellers?