Use app signing by Google Play - How to do update version test

Question

Please correct me!!

I read in this article: https://support.google.com/googleplay/android-developer/answer/7384423

App signing key (1) - managed by Google, is Inaccessible

Upload key (2) - is managed by us

(1) can be different with (2)

How can we obtain the (1) for signing in local?

I need to test update from current version (the latest one on PlayStore which is signed with 1) to the new version N+1. But since I can not have (1), how can I sign my app for local testing?

Thank you.

Answer 1

Thank Michael for your answer:

When you opt in to have your app signed by Google you can choose to provide an existing key rather than having a new one generated by Google: "To provide your own signing key for Google to use when signing your app, select Advanced options and select one of the options that lets you securely upload a private key and its public certificate". If you've already let Google generate a key for you then I'm not sure if you can redo it (especially if APKs signed with that key have gone out into production).But you could create an Internal Test group for your team and publish new versions there first