Ionic 3 and Google Play App Signing

I know I’m kind of late to the party on this, but I’m looking for steps on how to do this with an ionic app.

I think last fall to try the app bundle stuff I had uploaded our App signing certificate to Google thinking something would happen to our existing apps. I don’t think it did.

Now doing a brand new app, Google asked if I wanted to do App Signing by Google Play. I hit continue and tried to upload an APK signed. Didn’t work. Google knew I had signed it.

I have been trying to figure out what I really need to do.
I think I need to generate an upload key. Does has to be done in Android Studio? No command line?
Also on google play store under app signing I can download a certificate? Do I need this? What is this for?
How do the step for building/signing an apk from ionic change?
https://ionicframework.com/docs/v1/guide/publishing.html

Wondering if its just worth going back the old way?

I was having same issue i solved it by using

ionic cordova build android --prod --release
keytool -genkey -v -keystore my-release-key.keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 10000
jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore my-release-key.keystore HelloWorld-release-unsigned.apk alias_name
zipalign -v -p 4 HelloWorld-release-unsigned.apk HelloWorld.apk
apksigner sign --ks my-release-key.keystore HelloWorld.apk

If sign --ks my-release-key.keystore HelloWorld.apk gives any error
C:\Users\PC Name\AppData\Local\Android\Sdk\build-tools\29.0.3
Here you can find the akpsiger, The apksigner tool, available in revision 24.0.3 and higher of the Android SDK Build Tools. Add this in your The apksigner tool, available in revision 24.0.3 and higher of the Android SDK Build Tools, Add this to your path so that you can use apksigner.
Hope this will help.

Thanks for the info.
You uploaded your signed certificate to google.

Did you download something from google play to sign new apps?
Did you generate a new Key Store and Upload Key from Android Studio?

That is what you are using when you sign your release?

No, i didn’t download anything just these 5 commands and try to upload the apk.