If you are getting this error. "Your Android App Bundle is signed with the wrong key. Ensure that your App Bundle is signed with the correct signing key and try again.". You will need to use the right Keystore on the app build. 

Please make sure that you are using the original KeyStore that you submitted in your 1st build to the Google Play Store. It is your responsibility to save and keep safe that information. If you do not have it, you can contact us through a support ticket to assist you.