Since it emerged from the depths without a clear, simple answer :
Want to develop on your computer and just see preview of localhost / 127.0.0.1 on your phone, similarly as if you’d open it in the browser? Use ngrok, then on your phone just open the IP address it generates for you (works with hot-reloading, assets, etc. etc.)
Want to preview your code as an actual app deployed on your phone, not just a preview in the browser? Use Capacitor to build Android / iOS app, and just npx cap run android or npx cap run ios to deploy to a USB-connected device (it bundles the app in .apk / .aab / .ipa on each deploy, so it doesn’t support hot-reloading - but as a result you run your code as an actual WebView app, able to test all it’s pros and cons.)