Alright, from the error message, you need an Android development environment.
Follow the tutorials on this page:
Go through the Expo CLI installation process.
When testing your app, use a real Android device to scan the QR code to run the app.
Development OS: Windows?
Target OS: Android?
Have you done step 3 and 4?
Configure ANDROID_HOME environment variable
Add platform-tools to Path
This guy says in Jan 2020 that he has same problem as you, he solved by uninstalling and reinstalling Java
`Turns out I had a problem with my Java. I uninstall JDK and JRE and reinstall the latest version and it worked out for me.`
The Java JDK and JRE version must be latest.
calvin Don't worry, a Java expert will come up.
Just in case Danijel is busy, let me find one more Java expert I know.
Javier Felipe Toribio Is there something you can share with us, regarding JRE version, especially for Android Studio?
Danijel Ivanović must have missed my tag yesterday
Hello Danijel, have you used ReactNative with ReactNative CLI? Any chance you can help this asker?
Gordon Sorry my friend, I didn't work with.
calvin Maybe here you can find something useful :
Here is the error:
Error failed to install the app. Make sure you have the Android development environment set up: https://reactnative Dev/docs/getting-started.html#android-development-environment. run cli with --verbose flag for more details.
Error command failed: gradlew.bat app: installDebug-preactnativedevserverport=8081
Exception in thread "main" java.net.connectexception: connection timed out: connect
Yah I know that I was trying to use react-native with Android studio because expo has some limitations and I did go through the tutorials on the page and did everything that was asked but it's still giving me an error I think it's something to do with gradle