Advanced Security Threats to E-commerce & Their Solutions?

Hi E-commerce Folks!

I am new to this group and the E-commerce world as well. Although I have worked on mobile and app development projects but it is the first time when I am working in an e-commerce store. So, I would like to explore more about advanced security threats to e-commerce and their solutions.

First of all, if we discuss the security of a payment gateway or a safe payment system for an e-commerce site what do you guys suggest other than choosing a protected gateway, the right payment process and SSL protocol?

Likewise, I found many solutions to security threats in this article https://anyforsoft.com/blog/ecommerce-security-threats-and-solutions/ when come to payment fraud for e-commerce stores but what should a developer do if a fraud transaction is using a strong VPN layer to hide an IP address?

Also what other tips would you guys like to offer in this regard?

Waiting for your response.