How to use NEW Upload Key to sign app update and upload to Google Play store?

Hi,

Somehow I managed to save the wrong keystore for my Android app that I developed using Xamarin and already published.
When I wanted to upload an update to the Google Play Store with the keystore that I thought was the right keystore,
the SHA certificate did not match.

Luckily I was registered for Google Play App Signing so they were able to reset the Upload Key for me.
In order to reset the upload key I:

1. (dont know if i had to do this to generate new upload key) Generated a new archive and new keystore for the Android project in Xamarin and exported the APK to a folder. In that folder i ran the command lines in the next steps:

2. Generated a new upload key using the command line:
   keytool -genkeypair -alias upload -keyalg RSA -keysize 2048 -validity 9125 -keystore keystore.jks

3. Exported the certificate for that key to a *.pem file:
   keytool -export -rfc -alias upload -file upload_certificate.pem -keystore keystore.jks

4. Sent the *.pem to Google Play Developer Support.**

   Now that I have a *.pem file and *.jks file, how do I create the new APK file for my Xamarin Android project, signed with the new upload key in Visual Studio?