Third Party Emulators
Unlike Android Studio Emulator, your device will not appear in the device list with a simple reload. You must connect to it using the IP address to its ADB port. This can be done under the device tab using the IP button. Simply enter the address in the dialog and hit connect.
For all emulators you need to turn on USB debugging and change resolution to 2160x1080
Follow this guide to enable USB Debugging, root is not needed so you can skip step 3.
On the off-chance that connecting to IP is not working after you've enabled USB debugging, are on Android 7 and have resolution set then consult this FAQ to find the port: https://github.com/waicool20/WAI2K/wiki/FAQ#cannot-connect-to-port-62001-on-nox-emulator
USB Debugging is already enabled by default.
Orange MuMu does not work, it is not a true emulator and so it doesn't provide all of the Android functionality that ADB requires.
Go to settings and turn on Android Debug Bridge
Then you must enable compatibility mode or else the emulator client screen will turn black/not update after you run WAI2K
And optionally enable Hardware decoding of ASTC textures for better performance when using the optimized client