Upload signing key for bundle?

Hi All,

I'd like to try my first 64/32 bit upload to the Playstore, but it looks like I need to upload a signing key.

IGoogle says I must be enrolled in App Signing. I can see the Tab named App Signing, but it's unclear to me how to proceed.

Would I need to use the same key as was used for the existing app? To make sure it's a valid update to an existing app?

Export something from the Provisioning tab in the Project Options?

And how to upload? Google gives me examples based on Android Studio and Java stuff. How about Delphi?

Maybe I missed something on the Wiki...  If so, can someone provide me a link?