Update APK for Playstore : Urgent Requirement, Need to do today.

I need an existing web app's APK signed using Mighty Web Webview. The app is already on the Play Store; it just needs to be updated.

Requirements:
- Use the existing source code (which I have)
- No changes to web app URL or content
- Keystore file is available

Ideal Skills and Experience:
- Experience with Mighty Web Webview
- Familiarity with APK signing and Play Store updates
- Proficient in handling web app integrations