It looks like JWT-secured push notifications is relatively new. I either never noticed it or decided I didn't need it and forgot it existed. I do notice this note:
"This feature is currently in controlled availability. Contact Partner Success to enable JWT-secured push notification testing for your developer account."
https://developer.roku.com/docs/developer-program/roku-pay/quickstart/setting-up-web-services.md#tes...
It looks like for testing you want to use https://assets.cs.roku.com/keys/partner-jwks-test.json , but I don't see that "kid" there either.
That URL was found here:
https://github.com/rokudev/notification-receiver-sample/blob/main/src/main/java/com/roku/notificatio...
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