You can use a tool like MechDome . This service takes an Android APK and converts it into a standalone iOS app or an Xcode project. It works by virtualizing the Android API on top of iOS.
This likely violates copyright laws and the original app’s terms of service. You may also infringe on patents or trademarks. Only do this for your own apps or open-source projects. convert apk to ipa
The most promising future is in — like Google’s scabbia or giraffe projects — that can take a universal intermediate representation (IR) and spit out native code for both platforms. But you’d still need the source code, not just an APK. You can use a tool like MechDome
If you have the original source code, migrate it to a framework that can output both APK and IPA: This likely violates copyright laws and the original