Dual sim

Only iPhones, designed for specific markets, came with the option to support dual physical SIM cards. Most of the others support dual SIMs, but one being physical, and the other an eSIM. The newest iPhone models, sold for the U.S. market only have dual eSIMs.

You will need to provide more details on what exactly the issue is with your iPhone 12 Pro Max before we can help you.

"2 Dual SIM", that means you're want to using four different numbers on your iPhone, is that correct? iPhones unfortunately accepted only two SIM cards for using at the same time.

That is a US market phone. It has one physical SIM slot and one eSIM.