I have a existing App in Google Appstore that I would like to update. The existing App in the Appstore right now was not developed using React Native but the update that I now have that I want to upload is developed using React Native and I do not use Android Studio....
The keystore I used to sign the existing App cannot be found at all...I've lost it somehow (probably from reformatting the computer and on top of that I've sold that old computer).
Some articles online say that that with the new App Signing that GOogle Play provides, it gives the opportunity for existing App's with lost keystores to be updated as long as the App opts in to App Signing of Google Play. Is this true?
So I've gone to the Google Play store and tried to Opt-in the App Signing service that Google Play store provides.
I am faced with 3 possible options:
1.Upload a key exported from Android Studio
2.Export and upload a key from a Java keystore
3.Export and upload a key (not using a Java keystore)
Which one should I choose?
Let us say my old existing App's id that I assigned to it was the.id.i.gave.to.my.app.com
Since I've lost the keystore I've used to sign the old existing App, then I need to create a new keystore for this new version that I want to use to update the existing App...can I still use the same exact id? e.g. the.id.i.gave.to.my.app.com ?
Is this the right direction for updating a existing App in Google Play when the existing App's keystore has been totally lost?
tldr; You will have to create a new app, sorry :-/
The idea behind App Signing by Google Play is that Google signs your APK with the app signing key on your behalf. For that to happen, you need to transfer your app signing key to Google Play. Since you have lost it, that unfortunately can't happen, so you won't be able to enroll in that program.
What you have read is not about recovering lost keystores, but about changing the upload key (i.e. the key that signs the artifact you upload to the Play Console so that Google knows that it's effectively coming from you) rather than the app signing key (i.e. the key that signs the APK that is served to your users through the Play Store; that key cannot change*).
Your only option now is to either find that lost keystore, or create a new app. There is unfortunately technically no other solution.
*You may read in some places about "key upgrade" or "key rotation" but the former requires to be already enrolled in App Signing by Google Play, and the latter is not supported by Google Play and would still require you to have a hold of the original app signing key when performing the rotation anyway.