This can happen for a number of reasons. In short, you have to make sure that Java 8 is installed, the Android SDK Tools are installed, and USB debugging is enabled in the Android device:
1. In the Android device, go to Developer Options. How to reach Developer Options depends on the device and/or Android version. Usually it is in Settings -> System -> Developer options. In the Developer Options, there is section named "Debugging". In this section, there is an option "USB Debugging - Debug mode when USB is connected". Make sure you turn this ON.
2. Make sure you have installed Android SDK Tools.
(a) The "parent" folder containing the Android SDK should contain the following folders:
(b) The platform-tools folder includes a tool called "adb", which is responsible for connecting the Android device to the computer.
4. Now that you have installed the Android JDK and the Android SDK correctly, and you have enabled USB Debugging in the device, connect the device to your computer. You should see a dialog in the device asking you if you Trust this computer. Select Yes. Note that this dialog comes from the USB Debugging option, and it is not related to the Android Smart Lock. Thus the name of the computer will not appear in the list of trusted devices in the Smart Lock menu.
5. Now, if you navigate to the "Deployment" screen of LCFM Native, and the Android device is connected with USB to the computer, you should see the device identifier in the "Target Device" dropdown.