How to disable App Signing from Google Play Console

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.

1. "CREATE APPLICATION" having the same name which you want to upload before.
2. Click create.
3. After creation of the app now click on the "App releases"
4. Click on the "MANAGE PRODUCTION"
5. Click on the "CREATE RELEASE"
6. Here you see "Google Play App Signing" dialog.
7. Just click on the "OPT-OUT" button.
8. It will ask you to confirm it. Just click on the "confirm" button.

You are ready to Drop your APK file with your signing key. Just give it a try.

You can't disable App Signing after being activated as you can read in the image below:

Here you can find the official documentation, but the section of the screenshot has been removed. I will leave it here because it's still valid.

If you are stucked with it, you can follow the guide i posted here

If you haven't published yet, you can delete the app and then recreate it, and opt out of the google play app signing.