There're two ways to access the EQ setting with the WiiM Home App.
Method 1:  Go to the Now Playing page, tap the three dots (...) below the progress bar and there's EQ setting at the bottom. 

Method 2: Select the Device tab > tap the device setting gear icon > EQ

You can find the 24-preset EQ or customize your own EQ with the built-in 10-band graphic EQ tool.

The latest WiiM Home in the App Store has this 10-band EQ feature.