How can I disable App Signing from Google Play Console for all the apps already uploaded on Play store and for new apps?
You can't disable App Signing after being activated as you can read in the image below:
Took from official documentation.
If you are stucked with it, you can follow the guide i posted here
If Anyone is looking here because FIREBASE requires the new SHA1 fingerprint you can find it in the APP SIGNING screen and add it to your app for notification or authentication ....
We don't even have to change the JSON file that you have to include in your app.
You can delete your app, since it is still in the draft mode, and you can restart again, this time choose to opt-out even though it is recommended.
If you haven't published yet, you can delete the app and then recreate it, and opt out of the google play app signing.
Quoting the @MatPag you can't disable the app signing after activating it from Google Play Console. Here is the quick way to resolve this issue.
You are ready to Drop your APK file with your signing key. Just give it a try.