How does Xiaomi 5 set up the network?

Let me tell you how to set up a 4G network. If you want to choose another network, just select the network you need in the last step.

1) First, find and click Enter Mobile Network in the mobile phone interface settings, and open the data network in the mobile network settings. (as shown below)

2 Select Enable Data Network

3 First choose 4G network.

That's enough.