Does iPhone 12 pro max dual sim also support esim?

There are two main "versions" of that model:

1. Dual sim using 1 physical SIM card & 1 eSIM (worldwide, except countries mentioned at point #2).
2. Dual sim using 2 physical SIM cards (model sold for China, Hong Kong & Macau markets.

Regards

Giulio

1 esim

No the iPhone purchased in China that has 2 nano-SIM cards does not also have an eSIM.

Using Dual SIM with two nano-SIM cards - Apple Support

Using Dual SIM with an eSIM - Apple Support