Dual SIM system

I've recently got an iPhone 11 in Mainland China directly from Apple (meaning that it is unlocked). iPhones bought from Mainland China all have two physical nano SIM slots. I've already installed my Chinese number into the iPhone (main slot used), but I also want to put in my American number into the other slot. Is it possible that I can put two numbers of different countries inside the same phone, even if its unlocked?