I also have a H112-370 and unfortunately I can't make or receive calls using the sim from three. I was hoping it would at the very least support VOLTE to make calls even if it can't drop down from 4G/5G to 3G but no such joy as it doesn't even have the VOLTE page.
Hoping usual forums will come up with a flashable firmware which supports VOLTE but they still haven't found the points for the USB TTL cable