Thanks for contacting Google Play Developer Support.
Now that we’ve verified your account, I’m happy to help you reset the upload key for your app. The new upload key will be used to sign APKs that you upload to Play.
We recommend that you adjust your planning to include a buffer period of 48 hours from when the upload key has been reset before you can use the new upload key. You can learn more about using app signing by Google Play here.
Here’s how to generate and register a new upload key:
keytool -genkeypair -alias upload -keyalg RSA -keysize 2048 -validity 9125 -keystore keystore.jks
keytool -export -rfc -alias upload -file upload_certificate.pem -keystore keystore.jks
I look forward to your response.