Simple steps you need to go through to make it work with npx
sudo npm uninstall -g react-native-cli
sudo npm i -g npx
npx react-native run-android
More detailed explanation why this is happenig
Issue was that Facebook is not using anymore react-native-cli as they are using npx.
As stated in Facebook page:
If you previously installed a global react-native-cli package, please remove it as it may cause unexpected issues.
So i had to run sudo npm uninstall -g react-native-cli to remove react-native-cli
They also say that npx is shipped with nodejs but that wasn't my case.
React Native has a built-in command line interface, which you can use to generate a new project. You can access it without installing anything globally using npx, which ships with Node.js.
So I had to install it using sudo npm i -g npx
After installing npx then just need to run npx react-native run-android.
Be aware of npx before react-native run-android
Now you don't have any command react-native now we only have 'npx' and react-native run-android is just a parameter for npx. For ex. to start metro we should run npx react-native start
npm -v