You’ve 3 options according to me:
1 (easier): Create a service worker. Look for it on the internet. You can create a basic servie worker. Once Chrome detects it, it gives users an option to add the app to the homescreen. What it does is, it places your favicon in the app drawer o the Android phone and thus, it feels like a native app. It doesn’t show the URL, etc. Might get your work done. However, it can’t really be customised much. On the other hand, you don’t just get an Android app, you get an app that can be installed on all operating systems on which Chrome runs. Bonus: You can use this great tool from Microsoft: https://preview.pwabuilder.com/ (Not tried by myself).
2 (difficult): You can use Android Studio to make an app. Look for WebView implementation in Android. I had made once, I can share the source code, but, it’s useful only if you know Java. However, it’s a completely native Android app and thus, you can customise it the way you want.
3 (easy, not recommended): There are services like AppYet, etc., which can let you created an Android app with the URL of the website, but, it includes a lot of unwanted code and thus, the generated APK size is like 10MB (whereas, the one I made myself summed up in 2MB). There are a lot of unwanted and not-needed elements in such apps. Also, it’s not really very customisable. But, it can get the job done.