Hello Fadil

Not sure on how you can prevent the app from running on an emulator, but I know a way to discover if your app is on emulator or not.

• Create a javascript action called JSA_IsEmulator on your project
• Paste the code below on it

// This file was generated by Mendix Studio Pro.
//
// WARNING: Only the following code will be retained when actions are regenerated:
// - the import list
// - the code between BEGIN USER CODE and END USER CODE
// - the code between BEGIN EXTRA CODE and END EXTRA CODE
// Other code you write will be lost the next time you deploy the project.
import "mx-global";
import { Big } from "big.js";
import DeviceInfo from 'react-native-device-info';

// BEGIN EXTRA CODE
// END EXTRA CODE

/**
 * @returns {Promise.<void>}
 */
export async function JSA_IsEmulator() {
	// BEGIN USER CODE
	DeviceInfo.isEmulator().then((isEmulator) => {
		if (isEmulator) {
			console.info("EMULATOR");
			alert("EMULATOR");
		}
		else {
			console.info("NOT EMULATOR");
			alert("NOT EMULATOR");
		}		
	});
	// END USER CODE
}

• Call this javascript action from a Nanoflow
• Drag this Nanoflow in your Home_Native page to get an action button
• Install the package below in your JavaScript action folder

npm install --save react-native-device-info

After run your project you get the results below (it is a GIF animation, scroll right to see the emulator/device side by side and the correct emulator/not_emulator identification):

Maybe you canuse this lib and call the isEmulator method from the onload  event on the AppEvents widget  and block the usage of the app if isEmulator ==  true