React Native App not opening

I made a switch to React Native this month from Angular 7. My major attraction to this fascinating framework is the fast interaction of components (powered by babel for jsx) unlike the .ts controlled HTML templates in Angular 7 which sometimes need a refresh to update the GUI. The capability of HTML in js code is the peak of this framework transition.

I hope to find the relevant help I need here.

However, I am battling with the difficulty to create apk file from my React Native project using Android Studio. I succeeded in creating a signed apk which was installed on my Techno W2 device without any error; but the app isn't opening, and has no visible launch icon too. Although it is listed in the installed apps in settings. After installing, the 'open' button is inactive.

Any help on this will be greatly appreciated, as I cannot continue my React Native development unless this is resolved. I want to be creating my apk files locally, and not using Expo services which produce huge file sizes.
Note: My React Native Project is generated by 'expo init project-name', then ejected by 'expo eject' in order to regenerate the android & iOS directories.

Thank you.